Methods and apparatus for providing multi-source bandwidth sharing management

ABSTRACT

Methods and apparatus for providing one or more services such as video on-demand, switched digital video, or Internet services using shared bandwidth. Exemplary embodiments include methods and apparatus for providing video on-demand and switched digital video to a set of customer premise equipment devices using a first dedicated portion of the bandwidth to provide video on-demand services, a second dedicated portion of the bandwidth to provide switched digital video services, and a third portion of the bandwidth to provide both switched digital video and video on-demand services wherein the size of the bandwidth made available to provide video on-demand within the third shared portion of bandwidth varies as a function of requests for video on-demand and switched digital video services and the priorities of the new requests versus the existing operating services. Bandwidth management occurring in accordance with bandwidth sharing policies, priorities and rules generated by a bandwidth sharing mechanism.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/480,292 filed May 24, 2012 which is hereby expresslyincorporated by reference in its entirety.

FIELD OF INVENTION

The present invention relates to content delivery related methods andapparatus, and more particularly to methods and apparatus for providingone or more services such as video on-demand, switched digital video, orInternet services using shared bandwidth.

BACKGROUND OF THE INVENTION

Today, there are a variety of content distribution networks such ascable and satellite networks that are competing to bring various typesof services, e.g., digital television programming services, on-demandservices including video on-demand (VOD), MPEG video services, switcheddigital video (SDV) services, high definition television services,gaming services, and internet protocol services, to itscustomers/subscribers.

One of the ways that network operators try to distinguish themselvesfrom competitors is by trying to offer new, different and variedservices that will appeal to various segments of the public. For exampleby supplying dedicated entertainment services, e.g., programs thatappeal to a majority of their customers as well as programs that appealto specific portions of the population they can increase their customerbase and the revenues they generate. By way of example, sports fans maydesire a sports channel on which they can view programs dedicated tosporting events such as boxing events, football games, basketball games,soccer games, baseball games, volleyball tournaments, marathons, golftournaments, tennis matches, car races, cycling races, etc. Movie buffsmay wish to receive a video service that provides classic movies.Parents with young children may wish to receive video services providingcartoons. Others may wish any number of varied or different types ofservices such as new movie releases, dedicated news channels, Spanishlanguage channels, weather channels, etc.

In addition to the operators being able to distinguish themselves fromtheir competition by adding additional services, the network operatorscan also charge subscribers for premium or specialized services. Forexample, an operator may offer to its subscribers for a specific price,a video on-demand service wherein a subscriber can chose a movie from alisting of available titles and have the movie immediately transmittedto the subscriber's location. In addition, the subscriber may choose topay an additional amount to receive the movie in a high definitiontelevision format.

Customers' demands and expectations for additional services have alsobeen increasing. As the number of customers and the services they areprovided increases so too does the requirement for additional networkcapacity also referred to as bandwidth to support the additionalcustomers and services. For example, as more individuals buy highdefinition televisions, the number of subscribers requesting and/orexpecting entertainment programs be provided in high definitiontelevision format is also increasing. Programs transmitted in highdefinition television format require about four times the bandwidth ofthe same programs transmitted in standard definition television format.Nevertheless, to meet its subscribers' requests and expectations networkoperators have increased the number and variety of programs that theyprovide in high definition television format. In many instances thenetwork operator will provide a program in both standard definitiontelevision format and high definition television format. The ability tobring ever larger amounts of services (e.g., content and information) toan increasing number of customers/subscribers cheaply and efficiently isan on-going objective of network operators and directly affects anetwork operator's ability to sustain its customer/subscriber base andoverall profitability.

In content distribution networks, e.g., the aforementioned cable andsatellite networks, content, e.g., programs such as television shows ormovies are typically transmitted to customers as encoded, multiplexedand modulated signal streams, e.g., MPEG-2 streams. Content distributionnetworks can be implemented using a wide variety of differentarchitectures, configurations and components. One approach toimplementing a content distribution network is to use a broadcastswitching architecture with limited bandwidth.

From the above discussion it should be appreciated that in contentdistribution networks there is a need for allocating and utilizingbandwidth as efficiently as possible to maximize the usage of bandwidthin terms of revenue generating services and to providing subscribers thehighest level of satisfaction possible with the limited amount ofbandwidth available. While known attempts to address these needs haveobtained some level of success there remains a need for new and improvedmethods and apparatus for efficiently sharing bandwidth between avariety of services in a content distribution system.

SUMMARY OF THE INVENTION

The present invention addresses, among other things, the need forefficient use of bandwidth in content delivery systems. The inventionprovides new methods and apparatus for providing one or more servicessuch as video on-demand, switched digital video, or Internet services tocustomers using shared bandwidth.

One exemplary method in providing video on-demand and switched digitalvideo using bandwidth to a first set of customer premise equipmentdevices in accordance with the present invention comprises using a firstdedicated portion of the bandwidth to provide video on-demand services,a second dedicated portion of the bandwidth to provide switched digitalvideo services, and a third portion of the bandwidth to provide bothswitched digital video and video on-demand services wherein the size ofthe bandwidth made available to provide video on-demand within the thirdshared portion of bandwidth varies as a function of requests for videoon-demand and switched digital video services and the priorities of thenew requests versus the existing operating services. In some embodimentsthe video on-demand service priority of the method is a priority for avideo on-demand service and said switched digital video service priorityis a priority for a switched digital video service. This approachfacilitates efficient bandwidth sharing between VOD and SDV services.

In some implementations the system allocates bandwidth based on thepriorities of different services as determined from service priorityclassifications, rankings and/or features. A new service having a higherpriority than an exiting service or services may replace the existingservice or services that have a lower priority.

In one exemplary embodiment of the present invention, the VOD and SDVservice groups are aligned so that both service groups contain the samegroup of CPE devices. In addition to having separately dedicatednarrowcast bandwidth and QAM modulators for switched digital videoservices and video on-demand services, a portion of narrowcast bandwidthand associated QAM modulators that are allocated to the aligned servicegroups is sharable.

In some embodiments of the present invention a new messaging scheme isimplemented that simplifies the service discovery process andfacilitates the alignment of multiple and varied service groups, thealigned service groups corresponding IDs, and the CPE devices assignedto the aligned service groups thereby facilitating the sharing ofbandwidth allocated to the aligned service groups. In an exemplaryembodiment, which will be discussed in further detail below, a newmessaging scheme is provided for identifying video on-demand servicegroups. In the exemplary embodiment switched digital video and videoon-demand service groups are aligned by being assigned the same CPEdevices and service group IDs. With the alignment of the switcheddigital video and video on-demand service groups the ability to sharebandwidth to provide services for switched digital video and videoon-demand services to the CPE devices of the aligned services groups isfacilitated.

Furthermore, in at least one embodiment, the number of edge resourcemanagers is reduced as compared to known systems so that one resourcemanager manages requests for and allocation of resources necessary tofulfill requests for two or more services. For example, in someembodiments of the present invention a single edge resource manager isused to manage incoming requests for both switched digital video andvideo on-demand services and the allocation of resources, e.g.,bandwidth and edge QAM modulators, necessary to provide the requestedswitched digital video and video on-demand services.

In some embodiments of the present invention, a bandwidth sharingmechanism generates rules, policies and/or priorities that can be, andare, distributed throughout the components of the network to facilitatethe management and enforcement of efficient narrowcast bandwidth sharingfor a variety of services.

For example, in at least one particular embodiment a bandwidth sharingmechanism module centrally located in the headend generates rules,policies and/or priorities that can be, and are, distributed to edgeresource components located in one or more hub sites, e.g., edgeresource managers, to facilitate the management and enforcement ofefficient narrowcast bandwidth sharing for two or more services. One ofthe benefits of the distribution of rules, policies, and/or prioritiesto edge resources is the distribution of processing of requests to theedge resources eliminating processing and congestion in the headend aswell as the delay introduced in communicating service requests to theheadend for management of local resources to respond to requests. Thisdistribution of rules, policies, and/or priorities by which localresource managers can manage the provisioning of local resources, e.g.,modulators and bandwidth, in response to service requests makes theoverall system more efficient and quicker in responding to servicerequests.

In another embodiment, a bandwidth sharing mechanism module is centrallylocated, e.g., in a headend, and generates rules, policies and/orpriorities that are distributed to resource managers that control edgeQAM resources located in the hub sites. The resource managers, may beand typically are, centrally located in this embodiment but may also belocated in the hub sites. In some instances the resource managers areconcentrated physically in the same location, e.g., headend equipment,but are logically distributed. The distribution of the rules, policiesand/or priorities to the resource managers provides increased faulttolerance and facilitates local policy customization. One of thebenefits of this distribution of rules, policies, and/or priorities tothese resource managers is the distribution of processing of requestswhich can, and in some embodiments does, improve the overall performanceof the system versus relying on the bandwidth sharing mechanism moduleto conduct the enforcement and arbitration of the rules, policies and/orpriorities. In some embodiments similar efficiencies can be, and are,obtained by using multiprocessing or multithreaded processes in acentrally located server without distribution of the rules, policiesand/or priorities.

In at least one embodiment, bandwidth is managed so that it is fullyutilized or nearly fully utilized at all times. SDV streamscorresponding to SDV services without registered users are used tooccupy bandwidth not used for other services in at least someimplementations. This reduces the amount of time required to provide theSDV when a user registers for the service.

Various additional features and advantages of the present invention arediscussed in the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary content distribution network 100implemented in accordance with the present invention.

FIG. 2 illustrates portions of exemplary system 100 in greater detail.

FIG. 3 illustrates an optical transport ring that is utilized todistribute dense wave-division multiplexed (DWDM) optical signals to hubsites in accordance with one embodiment of the present invention.

FIG. 4 illustrates an exemplary allocation of bandwidth in accordancewith one embodiment of the present invention.

FIG. 5 illustrates an exemplary allocation of bandwidth in accordancewith one embodiment of the present invention.

FIG. 6, which comprises the combination of FIGS. 6A, 6B, 6C, 6D and 6E,illustrates the steps of an exemplary method for providing bandwidthresource allocation in accordance with one embodiment of the presentinvention.

FIG. 7 illustrates an exemplary VOD_SERVICE_GROUP_ID_DESCRIPTOR inaccordance with one embodiment of the invention.

FIG. 8 illustrates an exemplary VOD_SRM_IP_RESOURCE_DESCRIPTOR inaccordance with one embodiment of the invention.

FIG. 9 illustrates some of the implementation details of an exemplaryCustomer Premise Equipment (CPE) device in accordance with oneembodiment of the present invention.

FIG. 10 illustrates sample exemplary priority level designations forstream types in accordance with one embodiment of the present invention.

FIG. 11 illustrates sample exemplary priority level designations forprogramming package types in accordance with one embodiment of thepresent invention.

FIG. 12 illustrates sample exemplary priority level designations foron-demand types in accordance with one embodiment of the presentinvention.

FIG. 13 illustrates sample exemplary priority level designations forformat types in accordance with one embodiment of the present invention.

FIG. 14 illustrates sample exemplary priority level designations fortuner type in accordance with one embodiment of the present invention.

FIG. 15 illustrates sample exemplary priority level designations forviewership in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION

The current invention is applicable to various content distributionnetwork architectures. One exemplary architecture used to implement anexemplary embodiment in accordance with the present invention is abroadcast switched architecture. Such a network typically includes aheadend, hub sites, customer premise equipment (CPE) devices and acommunication network with limited bandwidth, e.g., a cable network.

The headend is controlled by an operator, e.g., a Multiple SystemsOperator (MSO), that determines what content is to be distributed to itscustomers/subscribers. Headends are generally centrally located systemswhile hub sites are network nodes that are typically located in closeproximity to the CPE devices to which they are connected and support.The switching gear, servers, Quadrature Amplitude Modulation (QAM)modulators and other equipment contained within a hub site are sometimesreferred to as edge devices because they are located at the edge of thecontent distribution network.

In various embodiments of the present invention, video on-demand contentis supplied to CPE devices via one or more video on-demand servers wherethe content is typically but not always stored. In some situations, thevideo on-demand content servers are not owned by the MSOs and, whileconnected to the content distribution network, are not located in theheadends or hub sites but the distribution of the video on-demandcontent is still controlled by the headends and/or hub sites. In somesituations, the video on-demand content servers may be, and are, locatedin one or more headends and/or hub sites.

Switched digital video services provide linear programming such as forexample scheduled video programming broadcasts, e.g., a news programscheduled to start at 10:00 p.m. and end at 10:59 p.m. In variousembodiments of the present invention, switched digital video content isnot stored on a server in the hub site but is instead a real timeprogram stream that is provided from the headend to the hub site andswitched onto a transmission medium, e.g., cable, to be distributed to aswitched digital video service group containing a plurality of CPEdevices. Switched digital video servers can be and often are owned bythe MSOs and are usually located in the hub sites and/or headends. Insome embodiments, the switched digital video server is a collection ofsoftware processes that control the binding and unbinding of streams tosessions, and manage the associated bandwidth. Unlike video on-demandservers, switched digital video servers generally do not directly handlemedia streams but instead the media stream is provided directly from aninternet protocol switch/router into the edge QAM at the hub site withthe switched digital video server managing the setup and connection. Theswitched digital video servers and associated modules are primarilyresponsible for acting as a termination point for requests from CPEdevices and for performing equipment bandwidth management functions suchas for example instructing the QAM modulators where a new video flowshould be carried within the multiple available QAM channels feeding aservice group, keeping track of all flows in those QAM channels, anddirecting tear-down of flows that are no longer desired. The switcheddigital video server also creates, updates and distributes theMini-Carousel stream to CPE devices via the switch-routers and QAMmodulators. The Mini-Carousel stream is a MPEG-2 compliant stream thatcontains client configuration, CPE device assignments, and a list ofservices currently streaming to each service group along with the tuninginformation to access each service. Each service group has its ownmini-carousel. A duplicate copy of this mini-carousel is carried on eachQAM channel operating in the service group to provide instant CPE accesswith no further tuning required. The switched digital video server alsoreceives service requests for switched digital video content from CPEdevices and responds to the CPE devices with the frequency and programnumber where the content may be found and the modulation depth used bythe QAM channel.

In some embodiments, other content servers such as for example videogame servers may be, and are, located in or associated with the contentdistribution network in a similar manner to the video on-demand and/orswitched digital video servers described above.

In one particular exemplary embodiment there are roughly 40 switcheddigital video servers providing switched digital video to populationsranging from 20 thousand to 25 thousand customer premise equipmentdevices, e.g., set top boxes per server. The aforementioned numbers areintended to be exemplary and not limiting. Each transmission medium,e.g., cable, in a system is connected to a group of homes, which containone or more CPE devices. The groups of CPE devices are referred to asservice groups. The headend and hub site equipment assign each CPEdevice to a particular group, e.g., switched digital video servicegroup, indicating the switched digital video server address to which theCPE device should send requests. A set of modulators, e.g., QuadratureAmplitude Modulation (QAM) modulators, usually located in the hub siteare assigned to the service group so that messages e.g., content andcontrol signals, can be modulated and sent to the CPE devices.

There are separate service groups for different services, for example,there is a video on-demand service group and a separate switched digitalvideo service group. One switched digital video server may supportmultiple switched digital video service groups. Each service group isassigned a service group ID by equipment in either the headend and/orthe hub site. One CPE device may, and usually does, belong to a numberof different service groups, e.g., a video on-demand service group and aswitched digital video service group. When a CPE device requests aservice it must identify the service group to which it belongs typicallyby identifying its service group ID. In known current systems theswitched digital video service group discovery process is different thanthe video on-demand service group discovery process. The use of separateprocesses and unrelated switched digital video and video on-demandservice group IDs adds additional complexity and equipment to currentcontent distribution systems. One aspect of the present invention is toalign one or more service groups, e.g., the switched digital video andvideo on-demand service groups, so they can use the same and/or similarservice group discovery processes, use less equipment to manage theservice groups, and obtain the ability to share bandwidth and equipmentto support the aligned service groups.

Services within the content distribution network are sometimescharacterized as multicast or unicast. Multicast services, e.g.,programs in the context of some video distribution systems, includeservices that can be viewed or consumed by two or more end-points at thesame time while unicast programs are those that can only be viewed orconsumed by a single end-point and/or user. Broadcast transmissions aresometimes referred to as multicast. An example of a multicast programtransmission in this sense of the term is a TV program that istransmitted to multiple end-points/users that starts at a pre-definedtime on a pre-defined channel and progresses linearly. Narrowcastservices are sometimes implemented as unicast services. An example of aunicast service is a program transmission such as a video on-demandprogram wherein a user selects a movie to view and has the ability tocontrol the video's playback such as start, rewind, forward, and pause.In the video on-demand unicast example, the video on-demand content isonly viewed by a single endpoint/user. While multicast video servicesoften include services which allow a group of viewers to view content atthe same or approximately the same time, such services are not limitedor constrained to use multicast IP. In the case of multicast IP, anindividual IP packet is delivered to multiple multicast group memberswho use the same multicast IP address. In contrast to multicast IPaddresses, each unicast IP address corresponds to only a singledestination device. In the case of SDV service to legacy MPEG CPE, theCPE is not provided with and does not require the IP address associatedwith a given video flow.

Various embodiments of the content distribution networks describedherein encounter capacity or bandwidth constraints that limit the numberand type of services that may be provided to customers/subscribers. Forexample, in various embodiments the transmission mediums that are usedto connect the content distribution equipment (e.g., video on-demand andswitched digital video servers) with the CPE devices have finite orlimited capacity to bear or carry information such as control signalsand data content. The capacity of a transmission medium to carryinformation is also referred to as bandwidth. As a result of thebandwidth limitations, there is a limited amount of information that canbe made available to the CPE devices at any one time. In some instancesthere are more requests for services than bandwidth available to supportthe requested services, which results in the blocking or denying of oneor more services and/or service requests.

In content distribution networks and in particular in broadcast switchedarchitecture networks, the way in which services are provided andbandwidth is typically utilized changes over time. For example, withvideo on-demand services the number of services being provided directlycorrelates to the number of service requests that are received. Theamount of bandwidth utilized is not only a function of the number ofrequests but the type of service request such as whether high definitiontelevision format is requested or standard definition television isrequested and whether the encoding rate is MPEG-2 or MPEG-4. Withrespect to switched digital video services the way in which the switcheddigital video services are provided and the bandwidth is utilized is afunction of a variety factors. One factor common to switched digitalvideo and video on-demand is the type of service being requested, e.g.,high definition television format or standard definition televisionformat. Another factor is whether the requested service is for picturein picture viewing which may, and in some implementations does, requireless bandwidth than a main screen video picture viewing. In someinstances, programs or services may be, and are, provided for use by alarge number of users while for other services there is only a smallviewership, and in other instances no CPE devices may be tuned into theservices. In content distribution systems that have only separatelydedicated switched digital video and video on-demand bandwidth theprovisioning of services is less than optimal. For example, SDV servicesare provided when no users are viewing or even requesting the servicewhile at the same time VOD requests are being denied because of a lackof bandwidth to provide the requested VOD service. Similarly, at othertimes VOD bandwidth is being held in reserve for potential future VODrequests which results in the blocking of requested SDV services whenthere is insufficient bandwidth. Moreover, there is neither servicelevel prioritization nor a mechanism between SDV services and VODservices to determine how narrowcast bandwidth should be allocated whenthere is insufficient bandwidth.

Narrowcast bandwidth for VOD services and QAM modulators associatedtherewith are usually dedicated to supporting unicast transmissions toCPE devices in a particular VOD service group. Similarly a separateallocation of bandwidth and QAM modulators associated therewith arededicated to providing switch digital video services to a particular SDVservice group.

In one exemplary embodiment of the present invention, the VOD and SDVservice groups are aligned so that both service groups contain the samegroup of CPE devices. In addition to having separately dedicatednarrowcast bandwidth and QAM modulators for switched digital videoservices and video on-demand services, a portion of narrowcast bandwidthand associated QAM modulators that are allocated to the aligned servicegroups is sharable. That is the bandwidth and associated QAM modulatorscan be used to provide either switched digital video or video on-demandservices. Exemplary bandwidth allocation diagram 400 of FIG. 4illustrates how the total bandwidth may be, and in some embodiments ofthe present invention is, allocated into three portions. The firstportion containing bandwidth dedicated for use in providing videoon-demand services 434, the second portion dedicated for use inproviding switched digital video services 418 and the third portionbeing sharable bandwidth 424 that can be, and is used, for providingswitched digital video and video on-demand services. Bandwidthallocation will be discussed in further detail in connection with FIGS.4 and 5. It should be noted that in some embodiments of the presentinvention the bandwidth may be, and is entirely sharable bandwidth. Insome embodiments of the present invention there is only sharablebandwidth and dedicated switched digital video bandwidth. In someembodiments of the invention there is only sharable bandwidth anddedicated video on-demand bandwidth. While the exemplary embodimentdiscusses the allocation and sharing of bandwidth based on two exemplaryservices, video on-demand and switched digital video, the invention canbe applied to the sharing of narrowcast bandwidth for any two or moreservices.

From the above discussion it should be appreciated that in contentdistribution networks there is a need for allocating and utilizingbandwidth as efficiently as possible to maximize the usage of bandwidthin terms of revenue generating services and to providing subscribers thehighest level of satisfaction possible with the limited amount ofbandwidth available. There is a further need to simplify the servicegroup discovery processes and align the switched digital video and videoon-demand service group IDs and discovery processes so as to simplifythe mechanism by which the CPE devices can identify the SDV and VODservice groups to which they belong.

In some embodiments of the present invention a new messaging scheme isimplemented that simplifies the service discovery process andfacilitates the alignment of multiple and varied service groups, thealigned service groups corresponding IDs, and the CPE devices assignedto the aligned service groups thereby facilitating the sharing ofbandwidth allocated to the aligned service groups. In an exemplaryembodiment, which will be discussed in further detail below, a newmessaging scheme is provided for identifying video on-demand servicegroups. In the exemplary embodiment switched digital video and videoon-demand service groups are physically and logically aligned by beingassigned the same CPE devices and service group IDs. With the alignmentof the switched digital video and video on-demand service groups theability to share bandwidth to provide services for switched digitalvideo and video on-demand services to the CPE devices of the alignedservices groups is facilitated.

Furthermore, in at least one embodiment, the number of edge resourcemanagers is reduced as compared to known systems so that one resourcemanager manages requests for and allocation of resources necessary tofulfill requests for two or more services. For example, in someembodiments of the present invention a single edge resource manager isused to manage incoming requests for both switched digital video andvideo on-demand services and the allocation of resources, e.g.,bandwidth and edge QAM modulators, necessary to provide the requestedswitched digital video and video on-demand services.

In some embodiments of the present invention, a bandwidth sharingmechanism generates rules, policies and/or priorities that can be, andare, distributed throughout the components of the network to facilitatethe management and enforcement of efficient narrowcast bandwidth sharingfor a variety of services.

For example, in one particular embodiment a bandwidth sharing mechanismmodule centrally located in the headend generates rules, policies and/orpriorities that can be, and are, distributed to edge resource componentslocated in one or more hub sites, e.g., edge resource managers, tofacilitate the management and enforcement of efficient narrowcastbandwidth sharing for two or more services. One of the benefits of thedistribution of rules, policies, and/or priorities to edge resources isthe distribution of processing of requests to the edge resourceseliminating processing and congestion in the headend as well as thedelay introduced in communicating service requests to the headend formanagement of local resources to respond to requests. This distributionof rules, policies, and/or priorities by which local resource managerscan manage the provisioning of local resources, e.g., modulators andbandwidth, in response to service requests makes the overall system moreefficient and quicker in responding to service requests.

In some embodiments of the present invention, the bandwidth sharingmechanism module includes a software rules engine that creates thenarrowcast bandwidth sharing policies. This software rules enginederives and/or is provided information and/or data about the variousservices in use in the network and in particular in the headend and hubsite nodes for which it is responsible for creating bandwidth sharingpolicies. In some exemplary implementations, the bandwidth sharingmechanism module's software rule engine creates a table of states andassigns a priority and/or policy to each service available to asubscriber of the system based on the information and/or data collectedregarding the service. In some variants of the embodiments of thepresent invention, the software rules engine parameterizing theinformation and/or data derived and/or provided regarding each serviceand creates a table of states and assigns a priority and/or policy toeach service available to a subscriber of the system based on theparameterized information and/or data. In some variants of theembodiments of the present invention, the software rules engineinitializes the table of states and priorities by assigning defaultvalues to each of the services based on overall system objectives andservice types such as pay services having a higher priority over freeservices.

FIG. 1 illustrates an exemplary content distribution network 100 havinga broadcast switching architecture implemented in accordance with thepresent invention. The exemplary system 100 includes external contentsources 108, a network headend 102, e.g., a cable network headend whichmay be located at a single building site, a plurality of K network hubsites 110 thru 112, e.g., cable network hub sites, a plurality ofcustomer premise equipment devices 116, 118, 120, 124, 126, 128, 132,134, 136, 116′, 118′, 120′, 124′, 126′, 128′, 132′, 134′, and 136′,e.g., set-top boxes, a communication link 132 coupling the externalcontent sources 108 to headend 102, a set of communication links 146including links 142 thru 144 coupling headend 102 to the plurality of Khub sites, and a plurality of communication links 114, 122, 130, 114′,122′, 130′, e.g., a hybrid fiber-optic coaxial (HFC) network of links,coupling the CPE devices to the K hub sites. Headends and hub sites aresometimes referred to as network nodes.

Exemplary headend 102 includes a plurality of devices/modules, e.g.,input/output (I/O) interfaces 134 and 136, memory storage 140, switcheddigital video/video on-demand (SDV/VOD) control module 104, switcheddigital video (SDV) path module 106, a processor 146 and communicationlink 138. Communication link 138 may be, and in some embodiments of thepresent invention is, a local area network that couples variouscomponents within the headend 102 including the I/O Interfaces 134, 136,memory storage 140, SDV/VOD control module 104, SDV media path module106 and processor 146. In addition to processor 146, other headendcomponents, e.g., SDV/VOD control module 104 and/or SDV media pathmodule 106, may, and in some embodiments do, include one or moreprocessors.

Headend 102 receives content, e.g., video streams, multimedia data,audio streams, and programming from a variety of external contentsources 108 via communication link 132 through I/O interfaces 134 whichmay, and in some embodiments, does include one or more receivers and/ortransmitters. Exemplary link 132 may be, and in some embodiments is, oneor more physical and/or logical bi-directional and/or uni-directionallinks for communicating content, control messages, signals and/or databetween one or more components of headend 102 and external contentsources 108. The type of physical transmission medium of the one or morelinks may, and in some embodiments does, vary. Exemplary links includewired and wireless links, e.g., fiber-optic cables, coaxial cables,satellite transmissions, microwaves and radio frequency waves.

Exemplary external content sources include satellite transmissions;terrestrial off-air; IP data networks; fiber-optic networks; videocontent storage servers, e.g., video on-demand servers, movie on-demandservers; audio content servers; storage media; content storagedatabases; game servers; emergency broadcast systems; and other networknodes. Headend 102 in some embodiments of the present invention inaddition to receiving content from one or more external sources alsocontains one or more content sources such as for example theaforementioned video on-demand servers, audio content servers, andcontent contained on storage media and/or in memory storage 140.

In the exemplary embodiment the headend 102 is coupled to hub site 1 vialink 142 of the set of communication links 146. Information, data,signals and content is outputted from I/O Interfaces 136 which may, andin some embodiments does, include one or more transmitters and/orreceivers to link 142. As discussed in connection with link 132, link142 and the other links that couple headend 102 to each of the hub sites1 thru K, e.g., link 144, may be, and in some embodiments are, one ormore physical and/or logical bi-directional and/or uni-directional linksfor communicating content, control messages, signals and/or data betweenvarious components of headend 102 and components of the hub sites. Thetype of physical transmission medium of the one or more links may, andin some embodiments does, vary. Exemplary links include wired andwireless links, e.g., fiber-optic cables, coaxial cables, satellitetransmissions, microwaves and radio frequency waves. Typically wiredlinks are used to couple the headend to the hub sites it controls.Information such as content is usually transmitted between the headendand hub sites as IP (internet protocol) data containing MPEG-2 transportstreams. FIG. 3 shows one exemplary embodiment of the set of links 146that couples the headend 102 to each of the K hub sites. In FIG. 3, theset of links 146 is implemented as an optical transport ring that isutilized to distribute dense wave-division multiplexed (DWDM) IP opticalsignals to each hub in the ring.

In the exemplary embodiment of FIG. 1, each of the plurality of K hubsites, 110, 112, is coupled to a number of customers'/subscribers' CPEdevices by a transmission medium such as for example a hybrid fiberoptic coaxial (HFC) cable network. Customer Premise Equipment (CPE)refers to any type of electronic device located in a customer's premisesor other suitable location and is coupled to the content distributionnetwork. Exemplary CPE devices include set-top boxes, digital videorecorders (DVRs), televisions, cable modems, embedded multimediapersonal adapters (eMTAs), and personal computers. FIG. 9 discussed indetail below depicts some of the implementation details of an exemplaryCustomer Premise Equipment (CPE) device 900 in accordance with oneembodiment of the present invention.

In the exemplary embodiment of FIG. 1 link 114, e.g., a HFC cableforming an RF trunk, connects a plurality N of CPE devices to hub site 1110. In the exemplary embodiment of FIG. 1, link 114 couples CPE devices(1A) 116, (1B) 118 thru (1N) 120 to hub site 1 110. The plurality of CPEdevices 116, 118 thru 120 coupled to hub site 1 110 via link 114 can,and in some embodiments does, form a first service group. Link 122similarly connects a plurality M of CPE devices (2A) 124, (2B) 126 thru(2M) 128 to hub site 1 110 and CPE devices 124, 126 thru 128 can, and insome embodiments does, form a second service group. There can be a totalof 9 services groups of CPE devices connected to the hub site 1 110. Aplurality of X CPE devices including CPE devices (9A) 132, (9B) 134 thru(9X) 136 can, and in some embodiments does, form the ninth service groupand are coupled to hub site 1 110 via link 130. Links 114, 122, and 130are any two-way suitable transmission medium capable of supporting theservices to be offered to the CPE devices in the service groupsconnected by the link. For example, the links may be, and in someembodiments of the present invention, are wired and/or wireless.Exemplary links include coaxial cable, fiber-optic cable, microwave, andsatellite network links.

The hub site 1 110 contains a variety of components includingdevices/modules for managing and allocating bandwidth to providerequested services, (e.g., switched digital video and video on-demandservices), servers, switches/routers, and modulators (e.g., QuadratureAmplitude Modulation (QAM) modulators)) which are used to selectivelyprovide the requested services to one or more CPE devices in theplurality of service groups supported by hub site 1 110 based upon oneor more service requests, the priority of those service requests, andthe amount of bandwidth available on the link connecting the requestingCPE devices to the hub site 1 110.

Each of the remaining plurality of hub sites connected to headend 102,the associated CPE devices, and coupling links operate in a similarmanner to hub site 1 110 and contain similar equipment and modules. TheCPE devices and links coupled to hub site K 112 bear numerical labelsthe prime of the numerical labels used in the description of similar CPEdevices and links in connection with hub site 1 110. The descriptionsprovided in connection with hub site 1 110 and the associated CPEdevices and links coupled thereto are also applicable to thecorresponding CPE devices and links bearing the prime numerical labelsin relation to the operation of hub site K 112 and the associated CPEdevices, links and service groups.

In some embodiments of the present invention, the SDV/VOD control module104 is responsible for the assignment of CPE devices to particular videoon-demand and switched digital video service groups and alignment of thevideo on-demand and switched digital video services to allow for thesharing of bandwidth to support switched digital video and videoon-demand service requests. In some embodiments the SDV/VOD controlmodule 104 is also responsible for managing, by for example, generating,applying, and distributing rules, policies and/or priorities for theallocation of bandwidth, e.g., shared and dedicated bandwidth, to beused to provide services such as for example switched digital video andon-demand services to CPE devices connected to the K hub sites connectedto and controlled by headend 102. In some embodiments, the SDV/VODControl module 104 includes a Session Resource Manager that isresponsible for allocating sessions of bandwidth in response to servicerequests, e.g., switched digital video service requests. In someembodiments, the SDV/VOD control module 104 is responsible forarbitrating between various service requests when insufficient bandwidthis available to support the current services and newly requestedservices. In some embodiments the SDV/VOD Control module 104 generatespriority tables to be used in the enforcement of narrowcast bandwidthsharing policies such as for example those shown in FIGS. 10, 11, 12,13, 14, and 15. In some embodiments of the present invention, theSDV/VOD Control module 104 includes a Bandwidth Sharing Mechanism modulepreviously described.

In the exemplary embodiment of the present invention, the SDV Media Pathmodule 106 is responsible for conditioning (e.g., encrypting, encodingand modulating) and selectively distributing requested content, e.g.,SDV content, by way of switches/routers from the headend to theplurality of hub sites.

Processor 146 of headend 102, may, and in some embodiments does, executesoftware program instructions stored in memory storage 140 to controlhardware and/or software in the headend to manage the receipt,processing, and transmission of control and content data signals intoand out of the headend 102. For example, in an embodiment processor 146executes instructions that command the switches/routers contained in theSDV Media Path module 106 to selectively distribute, i.e. transmit,content to the plurality of hub sites 1 thru K, 110, 112 via I/OInterfaces 136 over the plurality of links, 142 thru 144, coupling theheadend to the plurality of hub sites. The content selectivelydistributed to the hub sites is content either received from theexternal content sources 108 or was content contained/stored in theheadend.

In some embodiments content received from the external content sources108 via I/O Interfaces 134 is routed for storage in memory storage 140by the switches/routers in the SDV Media Path module 106 using link 138.The stored content is then available for transmission to the hub sitesat a later time. In some embodiments the SDV/VOD Control module 104 willsend control messages to the SDV Media Path module via link 138commanding it to retrieve the stored content, e.g., a movie, from memorystorage 140 and using the SDV Media Path module's switches/routers tooutput the content to one or more hub sites 1 thru K via I/O Interfaces136 in response to requests for service seeking the stored content,e.g., service requests from one or more customer premise equipmentdevices received by the SDV/VOD Control module 104.

FIG. 900 illustrates some of the details of an exemplary CPE device 900.CPE device 900 includes an I/O Interface 902 for interfacing with thecontent distribution network, e.g., link 114 of FIG. 1 which may be, andin some embodiments is, a part of a HFC network, a processor 908, amemory 910, an I/O Interface 920 for interfacing to one or more outputdevices, e.g, display devices, television sets (TVs), computers, videocassette recorders (VCR), digital video recorders (DVRs), set-top boxes(STBs), WIFI devices, routers, and other CPE devices. In someembodiments exemplary CPE device 900 may be, and is incorporated, into aTV, set-top box, DVR, etc. I/O interface 902 of CPE device 900 includesa receiver 904 for receiving communications such as for example controland data messages and/or signals, e.g., MPEG-2 messages, from equipmentin the distribution network via the communication link coupling the hubsite to the CPE device. The receiver can, and in some embodiments does,include one or more tuners. The I/O interface 902 also includes atransmitter 906 for transmitting messages and signals, e.g., requestsfor service to equipment in the distribution network via thecommunication link coupling the hub site to the CPE device. I/OInterface 920 of CPE device 900 includes a receiver 922 and atransmitter 924 for communicating with other devices, e.g., a displaydevice such as a television. CPE 900 also includes internalcommunication links 926, 928, 930 and 932, e.g., wires and/or wiretraces, for coupling various components within the CPE device therebyallowing for the communication of information, data, and control signalsbetween the various components. Communication link 926 may be, and insome embodiments is, a bus to which I/O Interfaces 902 and 920,processor 908 and memory 910 are coupled. Links 928 and 932 couple theprocessor to link 926 and memory 910 respectively. Link 930 couplesmemory 910 to the link 926. Memory 910 is used to store data as well asprogram instructions for the processor 908. In some embodiments of thepresent invention, CPE memory 910 may, and does include various types ofsoftware instructions including for example operating system software,client application software, program guide software, encoding/decodingsoftware, encrypting/decrypting software, client SDV software, clientVOD software, etc. CPE 900 sometimes also contains various specializedsoftware modules and/or hardware modules or circuits including ICs,digital signal processors, and/or ASICs that perform one or morededicated functions such as encoding and/or decoding MPEG-2 messagestreams, encrypting/decrypting messages, etc. In some embodiments, CPE900 contains software and/or hardware making it compliant with variousstandards and/or platforms such as the OCAP (open cable applicationplatform).

FIG. 2 is a diagram illustrating portions of exemplary system 100 ingreater detail. Elements of FIG. 2 which are the same or similar to theelements of FIG. 1 are identified using the same reference number.Diagram 200 includes headend 102, set of communication links 146, hubsite 1 110, and hybrid fiber coaxial (HFC) network 212.

Exemplary headend 102 in at least one embodiment of the presentinvention includes a Switched Digital Video/On-Demand Video Control(SDV/VOD Control) module 104 and a Switched Digital Video Media (SDV)module 106. The exemplary SDV/VOD Control module 104 includes a Sessionand Resource Manager (SRM) module 220 (hereinafter referred to asSession Resource Manager or SRM module), a Switched Digital Video (SDV)Manager module 224, a Video On-Demand Video (VOD) Manager module 222, aBandwidth Sharing Mechanism (BSM) module 226, an Element Manager Module228, External Applications 230 and 232, and communication links 234,236, and 238 for communicating signals, messages, and/or data betweenvarious components of the SDV/VOD Control module 104. Link 234 couplesBandwidth Sharing Mechanism module 226 with Session Resource Managermodule 220. Link 236 couples External Applications 230 and 232 with SDVManager module 224. Link 238 couples the SDV Manager 224, VideoOn-Demand Manager module 222 and the Session Resource Manager module220. The Session Resource Manager module 220 in some embodiments isresponsible for setting up sessions on resources. Exemplary resources,such as a QAM channel or group of QAM channels or the spectrum occupiedby one or more QAM channels or partial QAM channels, being capable ofcarrying a session load depending on the bandwidth of each sessionrequest (e.g., standard definition television format, high definitionformat, etc.). A QAM channel in one embodiment of the present inventionbeing a 6 MHz-wide Quadrature Amplitude Modulated RF carrier that isoutput by a QAM modulator to group of CPE devices.

Exemplary Switched Digital Broadcast Media Path module 106 includes astaging processor 250, a source program module 252, a bulk encryptionmodule 254, a Switch/Router 256 and communication links 258, 260 and 262for communicating signals, messages and/or data between variouscomponents of the SDV Media Path module 106. Link 258 couples bulkencryption module 254 to Switch/Router 256. Link 260 couples stagingprocessor 250 to Switch/Router 256. Link 262 couples source programmodule 252 to Switch/Router 256.

Communication link 248 couples staging processor 250 of the SDV MediaPath module 106 to Element Manager module 228 of SDV/VOD Control module104.

Exemplary hub site 1 110 includes the following components: a SwitchedDigital Video-Resource Manager/Switched Digital Video Server module 266,a VOD-RM/VOD Server module 271, an Edge Switcher module 274, QuadraturePhase Shift Key Modulators and De-Modulators 280, a set or pool ofthird-party Quadrature Amplitude Modulation Modulators 278, a set of orpool of Quadrature Amplitude Modulation Modulators 276 with encryptionfunctionality, a Combiner 282, a Cable Modem Termination System (CMTS)263 and various communication links 281, 284, 286, 288, 290, 292, 294,296, and 298 for communicating signals, messages and/or data betweenvarious components of the exemplary hub site 1 110 of system 100.

Communication link 142 of the set of communication links 146, is shownin FIG. 2 as including communication links 240, 242, 244, 245, 246, and264. Communication links 240, 242, 244, 245, 246 couple variouscomponents of the SDV/VOD control module 104 to various components ofhub site 1 110. Link 240 couples the Session Resource Manger 220 to theQAM modulators 276. Link 242 couples the Session Resource Manager 220 tothe 3rd Party QAM modulators 278. Link 244 couples the Session ResourceManager 220 to the local resource managers and servers in hub site 1110, e.g., Video On-Demand—Resource Manager 273, Video On-Demand Server272, Switched Digital Video-Resource Manger 270, and Switched DigitalVideo-Server 268. Link 245 couples Video On-Demand Manager module 222with VOD Server 272. Link 246 couples SDV Manager module Server 268 withSDV Server 268. The communication links 240, 242, 244, 245, and 246 areprimarily used for communicating control information, signals andmessages between the SDV/VOD Control module 104 and the hub site 1 110.

Communication link 264 couples Router/Switcher 256 of SDV Media Pathmodule 106 to Switcher/Router 274 of hub site 1 110. Communication 264is primarily used to communicate programming content and controlinformation, e.g., IP (internet protocol) data containing MPEG-2transport streams from the headend 102 to the hub site 1 110.

Exemplary SDV/VOD Control module 104 includes a Session Resource Manager(SRM) module 220 that is connected to the Video On-Demand VOD Managermodule 222 and Switched Digital Video (SDV) Manager module 224 via link238. The Session Resource Manager module 220 performs the initialswitched digital video resource pool setup based on requests via link244 from the Switched Digital Video-Resource Manager module 270 in hubsite 1 110. The Switched Digital Video-Resource Manager module 270 andSwitched Digital Video Server 268 may be, and in some embodiments of thepresent invention are, part of a combined Switched DigitalVideo-Resource Manager/Switched Digital Server module 266 located in thehub site 1 110. The Video On-Demand Resource Manager module 273 andVideo On-Demand Server 272 may be, and in some embodiments of thepresent invention are part of a combined Video On-Demand ResourceManager/Video On-Demand Server module 271. Additionally, in someembodiments the Switched Digital Video-Resource Manager/Switched DigitalServer module 266 and Video On-Demand Resource Manager/Video On-DemandServer module 271 are combined and operate on a single server/module265. This single module 265 operators as the combined resourcemanager/server for both switched digital video and video on-demandservices. In some embodiments, this single combined module 265 isreferred to as a universal resource manager or universal edge sessionresource manager. Links 244, 245, 246, 284 and 286 couple the componentsof the module 265 with Session Resource Manager module 220, VOD Manager222, SDV Manager module 224, QAM modulators 276, and 3rd Party QAMmodulators 278 respectively.

In some embodiments module 265 or one or more of the VOD-ResourceManager 273, VOD Server module 272, SDV-RM 270, or SDV Server module 268are located in the headend. In some embodiments, SDV Server module 268contains content to be inserted into SDV programming streams, e.g., adinsertion. In some embodiments no SDV Server module 268 is used when aswitched digital video resource manager module 270 is used. In someembodiments, the switched digital video server is also responsible forperforming the switching of switched digital video content.

The Session Resource Manager (SRM) module 220 in addition to performingthe initial switched digital video resource pool setup also arbitratesresource allocations between the Switched Digital Video-Resource Manager270 and the local resource managers of other services sharing the EdgeQuadrature Amplitude Modulators including for example, 3rd Party QAMModulators 278 and QAM Modulators 276 which are located in hub site 1110. Local resource managers refer to those resource managers located inthe hub sites. The Session Resource Manager module 220 will query theBandwidth Sharing Mechanism module 226 via messages over link 234 inorder to determine the parameters for which resources should beallocated when other local resource managers (such as for example theVOD Resource Manager 273) arbitrate for narrowcast bandwidth. TheBandwidth Sharing Mechanism module 226 may, and in some embodiments ofthe present invention does, exist as a logical component of the SessionResource Manager module 220. In some embodiments of the presentinvention, the Bandwidth Sharing Mechanism module 226 is embedded in theSession Resource Manager module 220. In some embodiments, the BandwidthSharing Mechanism module 226 is not embedded in the Session ResourceManager module 220 but is a separate module that is coupled to theSession Resource Manager module 220.

The Bandwidth Sharing Mechanism module 226 provides an instruction setto the Session Resource Manager module 220, the Switched DigitalVideo-Resource Manager 270, and other local resource managers such asVOD-Resource Manager 273. The Bandwidth Sharing Mechanism module 220drives the operation of the Session Resource Manager module 220 at theheadend 102 and the local resource managers at the hub sites, e.g.,Switched Digital Video-Resource Manager module 270 and Video On-DemandResource Manager 273, in a global and situational manner.

The Switched Digital Video Manager module 224 configures the system andassigns specific customer premise equipment devices (e.g., CPE devices116, 118, 120 of FIG. 1) to specific Switched Digital Video Servers(e.g., Switched Digital Video Server module 268). In some embodiments ofthe present invention, the CPE device communicates to the SwitchedDigital Video Manager module 224 over hybrid fiber coaxial network 212through hub site 1 110 when it is first initialized (e.g., at boot uptime) and the Switched Digital Video Manager module 224 provides thecustomer premise equipment device the address of the Switched DigitalServer to which it is assigned (e.g., the address of Switched DigitalVideo Server module 268 of FIG. 2). In some embodiments of the presentinvention, a file containing primary and standby customer premiseequipment device server assignments is carouseled to the CPE device fordetermining the switched digital server assignment. For example, thecarousel mechanism allows a CPE device that has not yet established atwo way connection to be initialized.

In some embodiments of the present invention, the Video On-DemandManager module 222 configures the system and assigns specific CPEdevices (e.g., CPE devices 116, 118, and 120) to specific VideoOn-Demand Servers, e.g., VOD Server 272 of FIG. 2.

In some embodiments of the present invention the Switched Digital VideoServer 268 is the termination point for channel change requests from theCPE devices. The Switched Digital Video Server 268 tracks what programsare being delivered to each service group of CPE devices. Upon receivinga request for a program from a CPE device, it verifies the presence ofthe program, and transmits the tuning information to the requesting CPEdevice via a message directed to the CPE device and/or via amini-carousel. If the requested program is not being delivered to theservice group to which the requesting CPE device is assigned, theSwitched Digital Video Server 268 requests the Switched DigitalVideo-Resource Manager module 270 to release a recaptured session andre-bind a new session to the service group to carry the requestedprogram.

In the exemplary embodiment, the Switched Digital Video Resource Managermodule 270 is a session and local resource manager located in the hubsite that is coupled to within the Switched Digital Video Server. Insome embodiments of the present invention the Switched Digital VideoResource Manager module is embedded within the Switched Digital VideoServer. In some embodiments it is a component in a module 266 thatcontains both the Switched Digital Video Resource Manager module and theSwitched Digital Video Server. The Switched Digital Video-ResourceManager 270 is connected to Edge Quadrature Amplitude ModulationModulators, 3rd Party QAM Modulators 278 and Quadrature AmplitudeModulation Modulators 276 via links 286 and 284 respectively. TheSwitched Digital Video-Resource Manager module 270 communicates with theEdge QAM modulators to direct the Edge QAM modulators to perform sessionrelease—setup provisioning sequence for resources currently under itslocal control under the direction of the Switched Digital Video Server268. This provisioning process results in the Edge QAM modulatorsjoining the multicast group and sending the MPEG-2 packets associatedwith the program to the appropriate output. In some embodiments thefunctions described above in connection with the Switched Digital VideoResource Manager module 270 and Switched Digital Video Server 268 arecombined into one module 266 as shown in diagram 200 of FIG. 2.

In some embodiments of the present invention, the Switched DigitalVideo-Resource Manager module 270 will send queries to the BandwidthSharing Mechanism module 226 via the links 244 and 234 to establish itsoperating parameters for service polices and priorities within theswitched digital video service. In some embodiments of the presentinvention, these service policies and priorities are contained in one ormore tables or memory locations within the Bandwidth Sharing Mechanismmodule 226 or associated memory such as memory storage 140 of FIG. 1.

In the exemplary system 100 as further described in FIG. 2, the SessionResource Manager module 220 located in headend 102 and the SwitchedDigital Video-Resource Manager module 270 located in the hub site arejointly responsible for the dynamic allocation of resources on the edgedevice and session setup. If the Switched Digital Video-Resource Managermodule 270 in the hub site is unable to perform session release—setupprocess, the Switched Digital Video-Resource Manager 270 negotiates withthe Session Resource Manager 220 for additional resources (e.g.,bandwidth). These interactions will follow the Bandwidth SharingMechanism module's 226 instruction set. The session release—setupprocess is the process wherein a resource manager releases a sessionpreviously bound to a service making the associated bandwidth availablefor use by another service and then sets up a new session with theavailable bandwidth binding it the new service requesting the bandwidth.

In some embodiments of the present invention, service priorities arecalculated using a ranking scale. Each service has one or moreattributes or characteristics sometimes referred to as features thatwill be valued in terms of classifications. These service priorities canbe, and are, used in arbitration to resolve narrowcast bandwidth usageconflicts between new service requests and currently operating serviceswhen there is insufficient narrowcast bandwidth available to supportboth the new service requests and the currently operating services. Thearbitration process may be, and in some embodiments of the presentinvention is performed in the Session and Resource Manager in theheadend (e.g., SRM 220). In some embodiments of the present invention,the arbitration process occurs in an edge or local session and resourcemanager module, such as for example SDV-RM module 270, located in thehub site 1 110. In some embodiments the arbitration process which occursin the edge session and resource manager is performed in accordance withinstructions and/or rules provided by the Bandwidth Sharing Mechanismmodule 226. In some embodiments the edge session resource manager moduleutilizes a table of service priorities provided by the bandwidth sharingmechanism in determining who to locate QAM modulators and bandwidth. Insome embodiments the edge resource manager, uses information provided byor derived from the CPE devices and/or current service bandwidthallocations in arbitrating the allocation of bandwidth among new servicerequests and existing services.

In an exemplary embodiment the Bandwidth Sharing Mechanism module 226functions as a policy generator and priority compiler to resolvebandwidth contention between services or streams within the narrowcastof bandwidth on the HFC network 212. In some embodiments, the BandwidthSharing Mechanism module 226 and/or Session Resource Manager module 220will perform the arbitration process based on rules, policies and/orpriorities generated by the Bandwidth Sharing Mechanism module 226. Insome embodiments, the Bandwidth Sharing Mechanism 226 will push, e.g.,send, at least some if not all of the rules, policies and prioritiesgenerated based on subscriber and/or system use cases to the resourcemanagers of various services such as switched digital video and videoon-demand. Pushing the rules, policies and priorities to the edgesession and resource managers (e.g., SDV-RM module 270 and VOD-RM 273)minimizes unnecessary traffic on the network and improves performanceversus relying on components in the headend to conduct the enforcementand arbitration. The Bandwidth Sharing Mechanism's policies dedicate howa service or stream is to operate within its allocated narrowcastbandwidth space and how priorities are to be used for the arbitration ofnew service requests. The Bandwidth Sharing Mechanism module 226generates policies for various operating cases and compiles a globalpriority based on a service's features or attributes. An exemplaryattribute is whether or not the service is active or inactive, i.e.,whether the service or stream being transmitted has one or more CPEtuners tuned to the service (i.e., active) or whether there are notuners tuned to the service (i.e., inactive). In some embodiments, thepolicies and priorities are then pushed or sent by the Bandwidth SharingMechanism module 226 to the local resource managers (e.g., via a set ofmessages sent via link 234 to Session Resource Manager 220 via link 244to VOD-RM module 273 and SDV-RM module 270) to maximize serviceefficiency. The policies dictate how a service operates in thenarrowcast bandwidth. The policies are applied by the receiving resourcemanagers in certain situations, e.g., when there is insufficientbandwidth to provide all requested services, to determine how thenarrowcast bandwidth (dedicated and shared bandwidth) will be allocated,to which services, and how those services will operate.

In some embodiments of the present invention, various associated servicecomponents, e.g., VOD-RM module 273 and SDV-RM module 270, enforcepolicies generated by the Bandwidth Sharing Mechanism module 226 byreceiving the policies from the Bandwidth Sharing Mechanism module 226at a specified time and/or by querying the Bandwidth Sharing Mechanismmodule 226 either before or upon the occurrence of a bandwidth conflictsituation requiring resolution.

In the exemplary embodiment, the Bandwidth Sharing Mechanism module 226contains a rules engine (e.g., software rules engine) that generates thebandwidth sharing policies based at least in part on informationderived, provided, or obtained about the various services in use. Insome embodiments, the Bandwidth Sharing Mechanism module 226 queriesvarious components of the headend, hub site and/or CPE devices to obtainat least some of the information that will be utilized in generating oneor more of the bandwidth sharing policies. For example, the BandwidthSharing Mechanism module 226 may, and in some embodiments does, sendmessages to the SDV Manager module 224 via Session Resource Manager 220and links 234 and 238 to determine how many and which CPE devices areassigned to a particular SDV service group for use in determining howmuch bandwidth should be allocated to the service group. In someembodiments, the Bandwidth Sharing Mechanism module 226 queries or isprovided information regarding the type and capabilities of the CPEdevices connected to the HFC network 212 and are associated withspecific service groups. For example, the Bandwidth Sharing Mechanismmodule 226, may, and in some embodiments, does obtain information aboutthe number of tuners supported by the various CPE devices in a servicegroup and in some instances statistics regarding the historicalsubscriber usage of services in certain situations upon which policiescan be based for the efficient usage of bandwidth in similar futuresituations. E.g., policies can, and are generated in some embodiments,based on the subscribers past subscriptions and viewership of highlypublicized sporting events such as NFL's super bowl football game,championship boxing matches and world series baseball games.

In the exemplary embodiment, the rules engine of the Bandwidth SharingMechanism module 226 creates a table of states and assigns a priority orpolicy to each of the services for which narrowcast bandwidth sharing isto be enforced based on the parameters collected regarding that service.This is referred to as the service state.

Existing services and new services are assigned a compiled priorityand/or policy based on certain parameters, and the service's operatingstate. This compiled priority and/or policy is created and controlled bythe Bandwidth Sharing Mechanism module 226. In the exemplary embodimentthere are two operating states: 1.) policy of operation and 2.) priorityof resolution.

The policy of operation state refers to when a service is beingdelivered on the narrowcast bandwidth. At this time the service isdeclared as in operation. While in operation a certain policy isassigned to that service. This assigned policy dictates how that serviceis handled within its operation.

The priority of resolution operation state refers to a new serviceoperating state. Rules generated by the Bandwidth Sharing Mechanismmodule 226 are used to arbitrate a condition among a new service requestto be delivered in the narrowcast bandwidth and already existingservice. In the exemplary embodiment, the objective is to have thenarrowcast bandwidth in use at all times or as close to continuously aspossible so as to make the most efficient use of the narrowcastbandwidth possible. In some embodiments, more than 90% of the dedicatedswitched digital video and shared bandwidth are continuously in use. Insome embodiments to achieve this objective, whenever there is unusednarrowcast SDV or sharable bandwidth available, a SDV service will beprovided on the unused bandwidth so that should a CPE device request theSDV service it will be readily available without any delay in theprovisioning of the service. Having narrowcast bandwidth in use at alltimes or as close to continuously as possible is sometimes referred toas max mode and also allows 2-way CPE devices to view currentlystreaming content even if the CPE devices upstream connections aretemporarily inoperative. Such CPE devices are sometimes referred to asnon-responders. This allows viewing of a stream by a non-responding CPEdevice to continue after the original requesting CPE device has left thestream, and also keeps the QAM pool filled with the most popularprogramming in a given service group to allow non-responders the bestpossible selection during upstream outages. In some embodiments,inactive switched digital video services are placed onto unuseddedicated switched digital video and shareable bandwidth to have thenarrowcast bandwidth full or nearly full as possible for a majority ofthe time. In some embodiments, an inactive switched digital videoservice without currently active viewers is placed onto the unusedbandwidth. Because of bandwidth fragmentation, it may not always bepossible to have all of the shareable and dedicated switched digitalvideo bandwidth occupied continuously.

In those embodiments in which the narrowcast bandwidth is full or nearlyfull for a majority of the time and/or all of the time, there are threearbitration states: 1.) replacing an existing inactive service, 2.)replacing an existing active service, and 3.) denying a service. A newservice request can be initiated by the subscriber, the operator, or theservice itself. Therefore it is important to assign a priority ofresolution to the new service that is being delivered. And, based on thearbitration state, the Bandwidth Sharing Mechanism module 226 enforces aseparate rule for each state that the new service will be in andarbitration occurs with the existing service's operating priority.

In an exemplary embodiment of the present invention, the BandwidthSharing Mechanism module 226 characterizes the existing bandwidth priorto generating and assigning bandwidth partition policy, bandwidth usagepolicy, and a bandwidth sharing enforcement policy based on thefollowing criteria. Bandwidth partitioning will be separated intonon-sharable bandwidth and sharable bandwidth.

Non-sharable bandwidth contains an equipment partition and a statisticalor logical partition. With respect to the equipment partition, if aportion of the modulators (e.g., QAM modulators 276 or 278 of FIG. 2) donot support bandwidth sharing, then those modulators are designated tooperate within the silo of the service to which they are assigned andthe service's policy and priorities. For example, if the modulator isequipment that is dedicated to providing bandwidth in support ofSwitched Digital Video service then the modulator will only supportthose switched digital video service and will operate within the policyand priority of the switched digital video service it is dedicated tosupporting. With respect to the statistical or logical partition, if aportion of the modulators (e.g., QAM modulators 276 or 278 of FIG. 2)are statistically or logically partitioned to be non-sharable, thenthose modulators are dedicated to operate within the policy andpriorities requirements of the service to which they have beenstatistically or logically partitioned to support, e.g., switcheddigital video or video on-demand. Only a service operating in thisdedicated non-sharable space is able to replace another service in thisspace. For example, if one of the QAM modulators in 3rd Party QAMmodulators 278 is logically partitioned to only provide bandwidth tosupport video on-demand services then only another video on-demandservice request can replace an existing video on-demand service. Thededicated video on-demand bandwidth controlled by the modulator cannotbe used to provide other services such as switched digital videoservices. The Bandwidth Sharing Mechanism module 226 will determine themodulators capabilities by querying the modulators (e.g., 3rd Party QAMmodulators 278 and QAM modulators 276) by sending messages via SessionResource Manager 220 via links 234, 240, and 242. In some embodiments,the Bandwidth Sharing Mechanism module 226 will determine the modulatorscapabilities by querying the equipment responsible for configuring thesystem and/or controlling the modulators such as the SDV Manager 224,Video On-Demand Manager 222, VOD-RM 273 and the SDV-RM 270.

The sharable bandwidth of the exemplary embodiment of the presentinvention contains a logical partition. The sharable bandwidth isdesignated by querying the appropriate resource manager, e.g., theVOD-RM 273 or the SDV-RM-270.

Diagram 400 of FIG. 4 shows how the total bandwidth 410 may be, and insome embodiments is, partitioned into three portions. A first portion ofthe total bandwidth is non-sharable bandwidth dedicated to providingVideo On-Demand services 434, a second portion of the total bandwidth isnon-sharable bandwidth dedicated to providing Switched Digital Videoservices 418, and a third portion of the total bandwidth is sharedbandwidth that is used to provide both switched digital video and videoon-demand services. The dedicated Video On-Demand bandwidth 434 may be,and in some embodiments of the present invention, is a result ofequipment partitioning such as QAM modulators that do not supportbandwidth sharing being and/or the result of logical or statisticalpartitioning. For example, the system may be, and in some embodiments,is configured to have a certain amount of QAM modulators dedicated toproviding bandwidth to video on-demand services because it is known thata certain amount of the bandwidth is likely to be in continuous use. Asa result the system assigns QAM modulators that are not capable ofsharing bandwidth and if necessary logically partitions additional QAMmodulators to ensure there is sufficient bandwidth to meet theanticipated video on-demand requests.

As discussed above, the Bandwidth Sharing Mechanism module 226 alsocharacterizes the bandwidth usage. Bandwidth usage is characterized aseither non-sharable bandwidth or sharable bandwidth. With respect tonon-sharable or dedicated bandwidth, new service requests for eachrespective service first seeks bandwidth within the non-sharablebandwidth space prior to seeking bandwidth in the sharable bandwidthspace. For example, a new service request for a video on-demand servicefirst seeks available bandwidth within the non-sharable or dedicatedswitched digital video bandwidth 434 prior to seeking bandwidth withinthe sharable bandwidth space 424. Similarly, a request for bandwidth tosupport a new switched digital video service first seeks availablebandwidth within the non-sharable or dedicated switched digital videobandwidth 418 prior to seeking bandwidth within the sharable bandwidthspace 424. With respect to sharable bandwidth, it is an objective tohave all sharable bandwidth be in use at all times. This serves toreduce non-responder impacts in conjunction with the switched digitalvideo channel map, e.g., when a subscriber tunes to a service that isbeing offered but is not being transmitted it will be readily availableto be tuned to instead of having to be allocated and supplied. As all oras much sharable bandwidth as possible is in use at all times, newrequests for service follow appropriate arbitration priority to replacean existing service. That is a request for service with a higherpriority than an existing service's priority will replace the existingservice with the lower priority. In FIG. 4, bandwidth segment 426 of theshared SD/VOD bandwidth is a segment of bandwidth that is being used toprovide a switched digital video service to which no CPE devices arecurrently tuned. When switched digital video service, e.g., televisionprogram, is transmitted to which no CPE devices are tuned the service isreferred to as an in-active service. There are 10 in-active bandwidthSDV services 414 using shared SD/VOD bandwidth shown in the exemplarybandwidth allocation shown in FIG. 4.

With respect to characterizing the bandwidth sharing enforcement policy,sharable bandwidth is bandwidth space that is available to all or someservices (e.g., video on-demand and switched digital video services) fordelivery of those services to CPE devices. FIG. 4 shows exemplary sharedSD/VOD bandwidth 424 with segments of the bandwidth in use for providingactive SDV services (e.g. 422), inactive switched digital video services(e.g., 426), and video on-demand services (e.g., 428). The BandwidthSharing Mechanism module 226 creates the policy and priority profilesfor placement or usage of the shared bandwidth for existing and newservices.

The Bandwidth Sharing Mechanism module 226 in an exemplary embodiment ofthe present invention creates or generates global policies based oninformation and/or parameters that are derived, queried from othercomponents of the system 100 or made available to the Bandwidth SharingMechanism module 226 from other components of the system 100. Exemplaryparameters include CPE device type, inactivity timeout, service stateclassifications, and blocking of service occurrences.

Exemplary CPE device type parameter is information as to whether a CPEdevice, e.g., CPE device 116, is one-way or two-way device. One-waydevices are not capable of receiving interactive services. As one-waydevices cannot access sharable services, the bandwidth sharing policiesand priorities are not applicable to one-way devices. Two-way CPEdevices are capable of receiving interactive services and accessingsharable bandwidth. As a result, the two-way CPE devices generally areexpected to adhere to the defined bandwidth sharing policies andpriorities of the Bandwidth Sharing Mechanism module 226. In someembodiments of the present invention, the system is designed such thatthe two-way CPE devices must adhere to the defined bandwidth sharingpolicies and priorities of the Bandwidth Sharing Mechanism module 226.

The two-way CPE devices which are to adhere to the Bandwidth SharingMechanism module 226 policies and priorities can be, and in someembodiments of the present invention, are further classified such as forexample as single tuner devices, multi-tuner devices, and/or deviceswith recording capabilities. Single tuner devices provide only mainscreen viewing. Multi-tuner devices provide picture-in-picture (PIP) andmain screen viewing. In some devices, one physical tuner is capable ofacquiring multiple MPTSs (multiple program transport streams) andoperating as if the single tuner were separate discrete tuners. Suchtuners are typically referred to as wideband tuners. They are common inDOCSIS-3.0 modems and are currently being introduced into set-top boxes.Though these devices only have a single physical tuner they areclassified as multi-tuner devices. Devices with recording capabilitiesprovide recording, PIP and main screen viewing. Additional exemplarydevice classifications of two-way devices can, and in some embodimentsof the present invention do, include video format type and encryptiontype the device is capable of utilizing.

An exemplary video consumption policy that the Bandwidth SharingMechanism module 226 may, and in some embodiments of the presentinvention, does generate is a policy concerning notifications. Forexample, notifications to the subscriber must be made available in theappropriate rendering format the subscriber is currently viewing (e.g.,high definition television format or standard definition televisionformat) when the video is consumed on the main screen; notifications tothe subscriber will not be displayed when video is consumed in the PIPscreen; and notification to the subscriber will not be displayed whenvideo is consumed in recording mode.

In some embodiments of the present invention, the Bandwidth SharingMechanism module 226 generates a timeout policy based at least in parton an inactivity timeout parameter. The inactivity timeout parameter isa designation of a period of time when a particular in use service in aservice group is not demonstrating any viewership activity as measuredby an activity event indicator. In some embodiments the timeout intervalis configurable. Exemplary inactivity timeout configuration parametersinclude default timeout interval, network service type timeout interval,time of day timeout interval, and subscriber timeout interval.

In some embodiments, there is a default timeout interval or period oftime after which the service being evaluated is designated as beinginactive for a particular service group. In some embodiments, thedefault timeout is configurable or derived to 0-24 hours in a minimum oftime increments such as for example ½ hour increments.

In some embodiments of the present invention, there is a configurablenetwork service type timeout interval and a policy that is enforceablebased on the network service type. This allows the Bandwidth SharingMechanism module 226 to generate individual time out interval policieson a service type basis. For example the network service providing thediscovery channel can, and in some embodiments does, have a four hourtime out interval while the network service that provides ESPN can, andin some embodiments does, have a 5 hour timeout interval. In thoseexemplary cases wherein the discovery channel service has a four hourtime out interval and the ESPN service has a five hour timeout interval,after four hours have passed without viewership activity on thediscovery channel the discovery channel service is designated asinactive. However, five hours of inactivity on the ESPN service isrequired before it will be designated as an inactive service.

In some embodiments, there is a time of day timeout interval parameterand policy. An exemplary time of day timeout interval policy is one thatis enforceable based on the time of day. For example, the BandwidthSharing Mechanism module 226 can configure or set for different times ofthe day a different time out interval indicating how long a lack ofviewership must occur before a service is designated as inactive at aspecific time of the day. For example, the primetime timeout period ofservices can, and in some embodiments of the present invention, is lessthan other times of the day such as early afternoon.

In some embodiments, there is a time out interval parameter and policythat can, and is, configurable and enforceable on an individualsubscriber basis. For example, a chronic non-button pusher subscriber(e.g., sports bar which does not change channels often so as to notinterrupt viewing activity) can be, and in some embodiments is,configured to have a longer timeout interval than other subscribers. Asthe subscriber time out interval policy is not a global policy for aservice group, it is necessary to determine if the subscriber for whichthe timeout policy has been established is tuned to the service ofinterest when making a determination as to whether the service should bedesignated as an inactive service based on the expiration of the timeoutinterval without activity.

In some embodiments of the present invention the Bandwidth SharingMechanism module 226 generates policies based on a service stateclassification parameter. The service state classification parameterclassifies services in one of two states: active and inactive. A serviceis in an active state when the service is in service and registeredviewers are active on the service. A service is in an inactive statewhen the service has been classified as inactive; or when no viewers arecurrently on registered using the service. An exemplary situation inwhich a service may be, and in some embodiments is, classified bysystem, e.g., the system's switched digital video resource manager, asbeing inactive is when the only CPE device tuned to the service has beeninactive for a period of time in access of a default timeout interval.

In some embodiments, the Bandwidth Sharing Mechanism module 226generates a bandwidth blocking occurrence policy based on parametersassociated with service blocking occurrences. For example, the BandwidthSharing Mechanism module 226 can, and in some embodiments does, generateand initiate alerting policies based on approaching or exceeding one ormore threshold levels of occurrences of service blocking includingindividual services and groups of services. For example, the BandwidthSharing Mechanism module 226 can, and sometimes, does generate ablocking occurrence alert policy, in which blocking should occur lessthan a certain percentage of the operating year for switched digitalvideo service, e.g., 2% of the operating year. The policy may, and insome embodiments of the present invention, does require tracking ofoccurrences of blocking of the service by the service group, e.g., bythe switched digital video service manager and/or switched digital videoserver supporting the service group. When occurrences of blocking of theservice in a service group exceeds the threshold set an alert isgenerated and made available to the system operator to take appropriateactions to reduce the occurrences of blocking. In some exemplaryembodiments, the alert may be, and is, generated by the Switched DigitalVideo-Resource Manager module 270 and transmitted to the SessionResource Manager 220 via link 244. The Session Resource Manager may theninstruct the SDV Manager 224 via messages sent over link 238 to assignadditional QAM modulators, e.g., from 3rd Party QAM modulators 278, tosupport the service group experiencing service blocking above thethreshold level. In some embodiments, the Session Resource Managermodule 220 may, and does communicate, the service blockage alert to theBandwidth Session Resource Manager module 226 via link 234 wherein inaddition to or in the alternative to adding additional QAM modulators tosupport the service group, the Bandwidth Sharing Mechanism module 226,may, and sometimes does, reassign service priorities and policies toaddress the service blocking issue and push the priorities and policiesout to the Switched Digital Video-Resource Manager module 270 supportingthe service group experience the service blocking issue. The BandwidthSharing Mechanism module 226 may, and in some embodiments does, also setnew blocking thresholds and/or alerts to monitor the occurrences ofblocking on the service group experiencing service blocking issues. Insome embodiments of the present invention, the Bandwidth SharingMechanism module 226 must generate and initiate alerting policies basedon service blocking occurrences.

In some embodiments of the present invention, service priorities arecalculated using a ranking scale. A service has a number ofcharacteristics or features that are valued in terms of classifications.These service priorities are then used in arbitration of new servicerequests versus existing operating services for limited resources, e.g.,narrowcast bandwidth and associated modulators. In some embodiments, thearbitration of new service requests versus operating services occurs atthe edge resource managers, e.g., Switched Digital Video-ResourceManager 270 which reduces delays in resolving conflicts and hence inproviding services, reduces traffic between the headend 102 and the hubsites, e.g., hub sites 110 thru 112, and offloads processing from theheadend, e.g., Session Resource Manager module 220.

In some embodiments there are both global conflict resolution mechanismsor rules and service conflict resolution mechanisms or rules. Oneexemplary global conflict mechanism or rule is that when a resourcemanager, e.g., SDV-Resource Manager 270, needs to arbitrate bandwidthallocation between a new service request and the existing operatingservices because there is insufficient narrowcast bandwidth available tofulfill the new service request, the resource manager, can, and in someembodiments does, use a priority ranking designation to determine whichservice will have priority over another. For example, a paid on-demandviewing event service may, and in some embodiments does, have a higherpriority than a free on-demand viewing event service. Similarly, aservice with many active users may, and in some embodiments does, have ahigher priority than another service with only one active user.

Once the global conflict resolution mechanisms or rules have beenexhausted and a new service request is still unable to secure narrowcastbandwidth then the resource manager, e.g., SDV-Resource Manager 270,uses a compiled service priority to determine arbitration between thenew service request and existing operating services. In someembodiments, where a new service request and an existing service requesthave equal compiled priorities the existing active service will havepriority and will continue to be provided the bandwidth necessary tocontinue service so as to not interrupt current subscribers currentviewing. In some embodiments, a service's compiled priority is the totalof each of the individual ranked service characteristics or features asdescribed below. The higher the compiled priority number the higher thepriority of the service. The compiled service priorities may be, and insome embodiments is, determined dynamically by the resource manager,e.g., Switched Digital Video-Resource Manager module 270, performing thearbitration operation to determine how the narrowcast bandwidth shouldbe allocated.

In an exemplary embodiment of the present invention, the BandwidthSharing Mechanism module 226 generally generates the global and serviceconflict resolution mechanisms/rules and provides them to the SessionResource Manager module 220, and the local resource managers included inthe hub sites such as the Switched Digital Video-Resource Manager module270 and Video On-Demand—Resource Manager module 273.

In an exemplary embodiment of the present invention, the BandwidthSharing Mechanism module 226, assigns priorities to each service basedon global and conditional designations. A priority designation thatimpacts a number of individual priorities in a global manner for theentire narrowcast bandwidth are referred to as global priorityclassifications and can include for example such classifications as:operating service (i.e., a service currently in operation), new service,and time of day. The Bandwidth Sharing Mechanism module 226 can, and insome embodiments of the present invention does, assign a specificpriority for each individual service feature such as for example: type:Stream Type, Programming Package Type, Stream Format Type, Tuner Types,Viewership Type, Network, and Program. Sample service prioritydesignations and rankings are shown in tables 1000, 1100, 1200, 1300,1400, and 1500 of FIGS. 10, 11, 12, 13, 14 and 15 respectively. Theseservice priority designations may be, and in some embodiments of thepresent invention are, generated by the Bandwidth Sharing Mechanismmodule 226 and stored in memory included in or associated with theSession Resource Manager module 220 in the headend and/or the SDV-RM 270in hub site 1 110. In various embodiments, the priority level servicedesignations are used by one or more of the session resource managers indetermining and assigning priorities to new service requests andexisting operating services based on global and service specificclassifications for narrowcast bandwidth arbitration purposes. For theseexamples, streams refer to transport streams and each service to beprioritized correlates to a single stream. It will be appreciated that arequest for a new service, e.g., new switched digital video service,will require a new stream while an existing operating service or streamis one that is currently being provided.

Table 1000 of FIG. 10 provides sample exemplary priority leveldesignations based on the global priority classification of whether theservice is an existing operating service or a new service and theservice specific priority classification of stream type. Each row 1012,1014, 1016, and 1018 of table 1000 correlates the priority to beassigned to a service based on its stream type shown in column 1002 andwhether that stream is a currently operating stream shown in column 1004or a new stream shown in column 1006. Row 1012 corresponds to a servicerequiring a new switched digital video stream, row 1014 corresponds to aservice that is an inactive switched digital video stream (I-SDV) thatis a stream that is currently being provided and is hence utilizingbandwidth but to which no CPE devices are currently tuned. Row 1016corresponds to a service which has an active switched digital videostream that is a stream currently in operation utilizing bandwidth andto which at least one or more CPE devices are currently tuned based onthe most recent tuning information obtained from the CPE devices withinthe service group. Row 1018 corresponds to a service for videoon-demand. An example of how table 1000 correlates service priorityvalues to services is now provided. The service priority value based onstream type for a currently operating video on-demand service is foundin the table 1000 entry for row 1018 column 1004 which correlates to VOD1018 and currently operating stream 1004. It is a value of 7. Theservice priority value based on stream type for a new video on-demandservice is found in the table 1000 entry for row 1018 column 1006 whichcorrelates to VOD 1018 and new stream 1006. It is a value of 5. Thecurrently operating VOD service has been assigned a higher priority thana new VOD service request. In some embodiments of the present invention,if there was insufficient bandwidth for both the currently operating VODservice and the new VOD service request, the session resource managerwould resolve the conflict by providing the bandwidth to the existingoperating VOD service because it has a higher priority value than thenew VOD service request.

Table 1100 of FIG. 11 provides sample exemplary priority leveldesignations based on the global priority classification of whether theservice is an existing operating service or a new service and theservice specific priority classification of programming package type.Each row 1112, 1114, 1116, 1118, 1120, 1122, 1124, 1126, 1128, and 1130of table 1100 correlates the priority to be assigned as a numericalvalue to a service based on its programming package type shown in column1102 and whether that service is an operating service currently using anoperating stream 1104 or a new service that requires a new stream shownin column 1106. The exemplary programming package types provided arebroadcast tier (simulcast) row 1112, cable tier (simulcast) row 1114,digital tier row 1116, sports & games tier row 1118, digital movie tierrow 1120, premium tier row 1122, Spanish/international tier row 1124,sport packages (e.g., NHL, NBA, NASCAR, NFL) row 1126, high definitionTV (HDTV) tier row 1128, and pay per view (PPV) event row 1130. Anumerical service priority value is assigned to each of these serviceprogramming package types based on whether the service is an existingservice or a new service requiring a new stream. In the example shown intable 1100 of FIG. 11, the higher the numerical value the higher thepriority ranking.

Table 1200 of FIG. 12 provides sample exemplary priority leveldesignations based on the global priority classification of whether theservice is an existing operating service or a new service and theservice specific priority classification of type of video on-demandservice. Each row 1208, 1210, 1212, 1214, and 1216 of table 1200correlates the priority to be assigned as a numerical value to a servicebased on its video on-demand service type shown in column 1202 andwhether that service is an operating service currently using anoperating stream 1204 or a new service that requires a new stream shownin column 1206. The exemplary video on-demand service types provided areFree On-Demand (FOD) row 1208, Subscription On-Demand (SOD) row 1210,Movies On-Demand (MOD) row 1212, Premium On-Demand (POD) row 1214, andStart Over On-Demand (SO) row 1216. A numerical service priority valueis assigned to each of these service video on-demand types based onwhether the service is an existing service or a new service requiring anew stream. In the example shown in table 1200 of FIG. 12, the higherthe numerical value the higher the priority ranking.

Table 1300 of FIG. 13 provides sample exemplary priority leveldesignations based on the global priority classification of whether theservice is an existing operating service or a new service and theservice specific priority classification of format type. Each row 1308and 1310 of table 1300 correlates the priority to be assigned as anumerical value to a service based on its format type shown in column1302 and whether that service is an operating service currently using anoperating stream 1304 or a new service that requires a new stream shownin column 1306. The exemplary format types provided are StandardDefinition (SD) row 1308 and High Definition (HD) row 1310. A numericalservice priority value is assigned to each of these service format typesbased on whether the service is an existing service or a new servicerequiring a new stream. In the example shown in table 1300 of FIG. 13,the higher the numerical value the higher the priority ranking.

Table 1400 of FIG. 14 provides sample exemplary priority leveldesignations based on the global priority classification of whether theservice is an existing operating service or a new service and theservice specific priority classification of tuner priorities. Each row1408, 1410, and 1412 of table 1400 correlates the priority to beassigned as a numerical value to a service based on the tuner priorityof the requesting entity and whether that service is an operatingservice currently using an operating stream 1404 or a new service thatrequires a new stream shown in column 1406. The exemplary tunerpriorities are Live Tuner—Main Screen row 1408 (e.g., service eitherprovided or to be provided to STB live tuner on which the video isprovided to the main screen), Live Tuner—Picture in Picture (PIP) row1410 (e.g., service either provided or to be provided to STB live tunerfor picture in picture display), recording tuner 1412 (e.g., serviceeither provided to or to be provided to STB recording tuner). Anumerical service priority value is assigned to each of these tunertypes based on whether the service is an existing service or a newservice requiring a new stream. In the example shown in table 1400 ofFIG. 14, the higher the numerical value the higher the priority ranking.

Table 1500 of FIG. 15 provides sample exemplary priority leveldesignations based on the global priority classification of whether theservice is an existing operating service or a new service and theservice specific priority classification of viewership. Row 1506 oftable 1500 correlates the priority to be assigned as a numerical valueto a service based on the active subscribers of the service and whetherthe service is an operating service currently using an operating stream1504 or a new service that requires a new stream shown in column 1506.The exemplary active subscriber priority is number or count of tuners1504 currently tuned to the service stream. For new services thepriority is set to 0 as there will be no active subscribers tuned to theservice.

When there is insufficient bandwidth to support a new service requestand global conflict resolution rules do not resolve the conflict,service conflict resolution rules may, and in some embodiments, areapplied. In such situations, a compiled service priority is generatedfor the new service and the existing services. This operation may be,and in some embodiments, is performed by the resource managerresponsible for resolving the service conflict. The compiled servicepriority is the sum of the total of each of the assigned priorities forthe service based on the service priorities features or attributes. Forexample, a new request by one CPE device's live main tuner for a premiumon-demand high definition format movie would have the following priorityvalues based on the exemplary priority values provided in tables 1000,1100, 1200, 1300, 1400, and 1500. Stream type is new stream on-demand sothe priority value from table 1000 is 5. The programming package type isnew stream premium tier so the priority value from table 1100 is 7. TheOn-Demand type is new stream premium on-demand so the priority valuefrom table 1200 is 7. The format type is new stream standard definitiontelevision format so the priority value from table 1300 is 4. The tunerpriority is new stream live tuner—main screen so the priority from table1400 is 4. The viewership priority which is the number of activesubscribers is 0 from table 1500 as this is a request for a new streamand therefore there are no active viewers. The compiled service priorityfor this exemplary new service request is 27 which is the sum or totalof the individual attribute or feature priority values for the requestedservice (i.e., 5+7+7+4+4+0=27). This compiled service priority value isthen compared to the compiled priority values of each of the existingoperating services with which it is competing for narrowcast bandwidthwithin the service group. The operating service compiled servicepriority value can be, and in some embodiments is, determined in thesame manner as the new service request compiled priority value describedabove. For example using the sample priority values of tables 1000,1100, 1300, 1400, and 1500, an operating service that has the followingfeatures: active switched digital video stream type (priority=7), sports& game tier type (priority=7), standard definition format type(priority=5), live tuner—main screen tuner type (priority=5), and 10active subscribers (priority=10 tuners) has a compiled service priorityvalue of 34. As 34 has a higher priority value than the compiledpriority value of the new service request which was 27. The new servicerequest is denied and the existing operating service maintains use ofthe bandwidth in content. Using the sample priority values of tables1000, 1100, 1300, 1400, and 1500, another operating service that has thefollowing features: active switched digital video stream type(priority=7), sports & game tier type (priority=7), standard definitionformat type (priority=5), live tuner—main screen tuner type(priority=5), and 1 active subscribers (priority=1 tuner) has a compiledservice priority value of 25. In this case the new service request has acompiled priority of 27 and the operating service to which it iscompared has a compiled service priority of 25 so the bandwidth would bereallocated to new service replacing the existing service through asession release and set-up process.

The compiled service priority values for operating services may be, andin some embodiments is, determined dynamically at the time of bandwidtharbitration. In some embodiments, the compiled service priority valuesfor operating services is determined statically and stored in memory inthe local resource manager or associated therewith for later use such asfor use in the bandwidth arbitration process. In some embodiments, someof the priority values for an operating service which do not vary overtime such as for example service programming package type, on-demandtype, and format type are determined when the service is placed intooperation and stored in memory for later use such as for use indetermining the operating service's compiled priority. In someembodiments, the priority values which vary over time for an operatingservice are determined periodically and stored in memory for use indetermining the service's compiled priority when a conflict arbitrationprocess occurs.

An example of the software messaging that enables the video on-demandand switched digital video service bandwidth sharing is now discussed inconnection with table 700 and 800 of FIGS. 7 and 8. The new softwaremessaging addresses the video on-demand (VOD) service group IP discoveryprocess and the video on-demand session resource manager IP address toprovide a tighter alignment of the narrowcast bandwidth capacity.Additionally, by changing by the video on-demand session resourcemanager IP address discovery mechanism, provides the ability to shiftmore gracefully away from using the legacy out of band (OOB) IP networks(e.g., QPSK Modulators and Demodulators 280 of FIG. 2) to communicatethe video on-demand service group IDs to the CPE devices. This newmessaging scheme provides a mechanism to distribute the session andresource manager process throughout the system which will reduce thesingle points of failure in the video on-demand sub-system.

Diagrams 400 and 500 of FIGS. 4 and 5 respectively illustrate exemplarybandwidth allocation and usage in accordance with the present invention.

Diagram 400 of FIG. 4 is now explained in greater detail. Legend 402shows active switched digital video frequency band 404, in-activeswitched digital video frequency band 406, and video on-demand frequencyband 408. Diagram 400 of FIG. 4 depicts bandwidth shown along ahorizontal frequency spectrum. In the example shown, the total bandwidth410 is partitioned into 37 frequency bands that are associated withmodulators for use in transmitting video on-demand and switched digitalvideo services to CPE devices in a service group. The bandwidth isapportioned into dedicated switched digital video bandwidth 418,dedicated video on-demand bandwidth 434 and shared switched digitalvideo and video on-demand bandwidth 424. The switched digital videodedicated bandwidth 418 includes 7 frequency bands, e.g., frequency band420, for use in providing switched digital video services to the CPEdevices of the service group. The video on-demand dedicated bandwidth434 includes 8 frequency bands, e.g., frequency band 430, for use inproviding video on-demand services to the CPE devices of the servicegroup. And, shared switched digital video/video on-demand bandwidth 424includes 22 frequency bands, e.g., frequency bands 422, 426, and 428,for use in providing video on-demand or switched digital video services.In some embodiments of the present invention, the SDV dedicatedbandwidth 418 and VOD dedicated bandwidth 434 is always active and inuse.

There are 12 frequency bands of active switched digital video depictedin diagram 400 indicating CPE devices are tuned into those frequencybands and receiving the service content being transmitted on thosefrequency bands. Five of the 12 active switched digital video frequencybands are part of the shared SD/VOD bandwidth 424 which includes a totalof 22 frequency bands. There are 10 in-active switched digital videofrequency bands depicted in the In-Active SDV bandwidth 414 being usedfrom the 22 frequency bands allocated to the shared SD/VOD bandwidth424. The in-active switched digital video frequency bands containcontent for a switched digital video service but no CPE devices arecurrently tuned to those in-active switched digital video servicefrequency bands. There are 15 frequency bands allocated for providingvideo on-demand services VOD bandwidth 416. Seven of the frequency bandsare part of the 22 frequency bands included in the shared SD/VODbandwidth 424 and the remaining eight frequency bands are from the VODdedicated bandwidth 434. There are no in-active video on-demandservices.

Diagram 500 of FIG. 5 is now explained in greater detail. Legend 502shows active switched digital video frequency band 504, in-activeswitched digital video frequency band 506, and video on-demand frequencyband 508, and unused frequency band 509. Diagram 500 of FIG. 5 depictsbandwidth shown along a horizontal frequency spectrum. In the exampleshown, the total bandwidth 510 is partitioned into 38 frequency bandsthat are associated with modulators for use in transmitting videoon-demand and switched digital video services to CPE devices in aservice group. The bandwidth is apportioned into dedicated switcheddigital video bandwidth 518, dedicated video on-demand bandwidth 534 andshared switched digital video and video on-demand bandwidth 524. Theswitched digital video dedicated bandwidth 518 includes 7 frequencybands, e.g., frequency band 520, for use in providing switched digitalvideo services to the CPE devices of the service group. The videoon-demand dedicated bandwidth 534 includes 8 frequency bands, e.g.,frequency band 530, for use in providing video on-demand services to theCPE devices of the service group. And, shared switched digitalvideo/video on-demand bandwidth 524 includes 23 frequency bands, e.g.,frequency bands 522, 526, and 528, for use in providing video on-demandor switched digital video services.

There are 12 frequency bands of active switched digital video 512depicted in diagram 500 indicating CPE devices are tuned into thosefrequency bands and receiving the service content being transmitted onthose frequency bands. Five of the 12 active switched digital videofrequency bands are part of the shared SD/VOD bandwidth 524 whichincludes a total of 23 frequency bands. There are 18 in-active switcheddigital video frequency bands depicted in the In-Active SDV bandwidth514 being used from the 23 frequency bands allocated to the sharedSD/VOD bandwidth 524. In accordance with one embodiment of the presentinvention all shared bandwidth is to be in use at all times so as tomake the most efficient use of the bandwidth as possible. As a result,any time shared bandwidth is released a new active or in-active switcheddigital video service will be allocated for use of the bandwidth. Thisserves among other things, to reduce non-responder impacts inconjunction with the SDV channel map. Furthermore, having an in-activeservice provided to the service group in bandwidth that otherwise wouldnot be in use is efficient in that if a CPE device requests the serviceit will already be available to the CPE device without any delay oradditional allocation. In this way the system is proactivelytransmitting or “pushing” services, e.g., video content, out to servicegroups of CPE devices so that the content will be available to expectedviewers. The services which are transmitted may be, and in someembodiments, are determined based on predictive factors such as pastviewing habits, service registration, and promotion of the service.There are 4 frequency bands allocated for providing video on-demandservices VOD bandwidth 516. These four frequency bands are part of theeight frequency bands of VOD dedicated bandwidth 534. Note that in thisexemplary embodiment there are also 4 frequency bands in the VODdedicated bandwidth spectrum 534 that are unused including frequencyband 528. This is so because in this exemplary embodiment there are only4 on-going video on-demand services being provided and the remaining VODdedicated bandwidth has not been allocated but is available for use inresponse to new video on-demand service requests.

In some embodiments of the present invention, when a service becomesin-active because there are no viewers currently registered as using theservice, i.e., no viewership, the system performs a bandwidth sessionrelease regardless of whether the bandwidth is SDV only, VOD only orshared bandwidth. The bandwidth session release process results in thebandwidth allocated to the in-active service being recovered so that thesystem can quickly allocate the bandwidth to newly requested services.This operation is sometimes referred to as min mode and typicallyresults in better packing efficiency. That is the ability to groupcontiguous bandwidth spectrum together. Various services require morecontiguous bandwidth than others such as HDTV versus SDTV services. Thisefficiency however comes at the expense of loss of viewing to CPEdevices that have gone non-responding.

Table 700 of FIG. 7 provides an exemplaryVOD_SERVICE_GROUP_ID_DESCRIPTOR in accordance with an exemplaryembodiment of the invention. Column 702 provides the syntax, column 704identifies the number of bits and column 706 identifies the format. Row708 identifies the VOD_SERVICE_GROUP_ID_DESCRIPTOR. Row 710 providesinformation corresponding to the VOD_SERVICE_GROUP_ID_DESCRIPTOR'sDescriptor Tag field. The DESCRIPTOR TAG is an 8 bit unsigned integerthat has the value 0X08, identifying this descriptor as aVOD_SERVICE_GROUP_ID_DESCRIPTOR. Row 712 provides informationcorresponding to VOD_SERVICE_GROUP_ID_DESCRIPTOR's Descriptor Lengthfield. The DESCRIPTOR_LENGTH is an 8-bit unsigned integer that has thevalue 0X04 that specifies the length in bytes immediately following thisfield up to the end of the descriptor. Row 714 provides informationcorresponding to the VOD_SERVICE_GROUP_ID_DESCRIPTOR's Service Group IDfield. The SERVICE_GROUP_ID is a 32-bit unsigned integer that specifiesthe service group identifier (SG ID) used to communicate the narrowcastspectrum of the client with the video on-demand session setup protocol(SSP) session resource manager (SRM). This ID may be the same ordifferent from the switched digital video service group ID descriptor.In some embodiments of the present invention, for those sites havingmodulators capable of sharing bandwidth the video on-demand and switcheddigital video group identifiers are the same.

Table 800 of FIG. 8 provides an exemplary VOD_SRM_IP_RESOURCE_DESCRIPTORin accordance with an exemplary embodiment of the invention. Column 802provides the syntax, column 804 identifies the number of bits and column806 identifies the format. Row 808 identifies theVOD_SRM_IP_RESOURCE_DESCRIPTOR. Row 810 provides informationcorresponding to the VOD_SRM_JP_RESOURCE_DESCRIPTOR's Descriptor Tagfield. The DESCRIPTOR_TAG is an 8 bit unsigned integer that has thevalue 0X09, identifying this descriptor as aVOD_SRM_IP_RESOURCE_DESCRIPTOR. Row 812 provides informationcorresponding to the VOD_SERVICE_GROUP_ID_DESCRIPTOR's Descriptor Lengthfield. The DESCRIPTOR_LENGTH is an 8-bit unsigned integer that specifiesthe length in bytes immediately following this field up to the end ofthe descriptor. Row 814 provides information corresponding to theVOD_SERVICE_GROUP_ID_DESCRIPTOR's IP_Port field. The IP_Port field isused to indicate the listening port of the video on-demand sessionresource manager that the client, i.e. CPE device, shall connect to. Row816 provides information corresponding to VOD_SRM_IP_AddressVOD_SRM_IP_Address field. The VOD_SRM_IP_Address field is used toindicate the IP address of the VOD session resource manager that theclient, i.e. CPE device, shall connect to. Row 818 provides informationcorresponding to the VOD_SERVICE_GROUP_ID_DESCRIPTOR's RESERVED field.The RESERVED field is a field that is not currently used but is reservedfor potential use in the future.

The following describes how the enablement mechanism or process forthose universal session resource manager (USRM) hub sites wherebandwidth sharing is enabled. First the switched digital video server,e.g., SDV Server 268 populates the fields of theVOD_SERVICE_GROUP_ID_DESCRIPTOR and VOD_SERVICE_GROUP_ID_DESCRIPTOR. Itpoints to the USRM in the IP_PORT and VOD_SRM_IP_ADDRESS fields and usesthe same SG ID as switched digital video when populating theService_Group_ID field. Second, the client code provided to the CPEdevices is updated so the CPE devices stop using the service group mapfile and instead uses the data in the descriptors. The CPE devices willget the descriptors on boot, so this step of the process is directed tohaving the client in the CPE devices no longer execute code to discoverCPE devices service group through use of the service group map file. Theelimination of executing this map file service group discovery codeshould make the CPE devices more efficient and speed up service requestsand tuning Third, as the CPE device clients start using the directaddress to the USRM, the VSM is still able to distribute VOD SRM sessionrequests to the owning USRM, so there is no impact on the viewer as thechange is implemented across the system. Four, after the period of timethe system operators identify any CPE devices making requests on the VSMas not getting the code upgrade and provide it the code upgrade. Five,eventually the VSM is no longer needed and the video on-demand isdistributed to the appropriate USRM that has already been doing all thework setting up sessions on the encryptors and QAM modulators.

The enablement mechanism or process for sites where bandwidth sharing isnot enabled includes the following steps. First, the system provides theVOD descriptor to the service group ID that matches the switched digitalvideo service group. This requires that the VSM track the resource toswitched digital video service group level. Second, the system uses aconfigured IP address to instruct the CPE devices client software to usethe VSM for the SRM for VOD sessions. Third, sessions flow to the VSM inthe same manner as when the CPE devices used the file-based VOD servicegroup discovery mechanism. Mechanisms should also be implementedproviding updates to the CPE devices when their video on-demand servicegroup ID changes for example when the service group is split into two orwhen the IP address changes because the service group was moved to a newVSM or USRM.

The use of this software messaging scheme forces the alignment of theswitched digital video and video on-demand service groups, locks in thebandwidth sharing benefits, and requires a common narrowcast. While itmay seem that a system operator loses capability and flexibility withthis alignment of the video on-demand and switched digital video servicegroups and sharing of bandwidth, the simplicity of operations and systemdesign act to unify the narrowcast capacity across the operators varioussystems.

Having separate SDV and VOD descriptors and service group IDs providessystem operators the flexibility to provide SDV and VOD services usingseparate SDV and VOD session and resource managers. By aligning the SDVand VOD service groups and associated IDs it also allows for bandwidthsharing to occur between separate session and resource managers.Policies, priorities, and rules governing when one session and resourcemanager may utilize bandwidth that is being managed by a differentsession and resource manager, may be and in some embodiments is,generated by SRM module 222 located in the headend 102 and distributedto the separate session and resource managers managing local QAMmodulators supporting separate service groups. For example, in the casewhen a first session and resource manager does not have sufficientbandwidth to support newly received service requests, that resourcemanager may request bandwidth assigned to a second session and resourcemanager supporting a separate service group prior to issuing a denial ofservice. In this example, whether the bandwidth assigned to the secondsession and resource manager will be made available to the first sessionand resource manager will depend on the whether the priority of the newservice request is greater than the priority of the services currentlyoperating in both the first and second service groups.

In some embodiments of the present invention, parent and child servicegroups are implemented wherein one service group, the parent servicegroup, completely encompasses all of the CPE devices of two or moreservice groups referred to as child service groups. This allows thechild plus the parent to service the child's CPE devices, but each childcan only service their own CPE devices. This concept can be extended forany number of levels of parent and child service groups. The followingis an example of using parent and children service groups. In thisexample, a parent service group contains CPE devices 1 thru 30, thefirst child service group contains CPE devices 1 thru 10, the secondchild service group contains CPE devices 11 thru 20 and the third childservice group contains CPE devices 21 thru 30. If service A is providedto the parent service group then all CPE devices 1 thru 30 can accessservice A. That is each of the CPE devices that are part of the first,second and third child service groups can access the service A. However,if service B is only provided to the first child service group then onlythe CPE devices in the first service group can access service B that isCPE devices 11 thru 20. The CPE devices in the second and third servicegroups cannot access service B. In an exemplary bandwidth sharing policywhich utilizes parent and children service groups, switched digitalvideo services are provided to a parent service group so that thoseservices can be accessed by any of the CPE devices in any of itschildren's service groups while VOD services which are always unicastare prioritized such that they are provided using a child service groupbandwidth over using the shared parent service group bandwidth. Aspreviously discussed in a typical large system, there are roughly 40switched digital video servers providing switched digital video topopulations ranging from 20K to 25K CPE devices per server. Theseservers respond to requests for millions of tunes daily and can, and do,handle the few additional tens of thousands of session setup protocolsessions for those subset of CPE devices. Providing a discrete number ofCPE devices talking to one SRM makes a large and small system look thesame. It reduces the need for any one SRM to continue to grow in sizeuntil it breaks.

Additionally, CPE devices within the system which are not using the QPSKOOB network to sign on to the network will not have to re-invent the waythey receive the SRM IP Address. Any CPE devices operating with sessionsetup protocol are in lock step with switched digital video and readingthe descriptors is already being performed.

FIG. 6, which comprises the combination of FIGS. 6A, 6B, 6C, 6D and 6Eshows the steps of a method 600 for providing narrowcast bandwidthresource allocation in accordance with one exemplary embodiment of theinvention. The method 600 allows a system to efficiently utilize sharedand dedicated narrowcast bandwidth to provide video on-demand andswitched digital video services to a set of customer premise equipmentdevices, e.g., set top boxes assigned to a service group.

The method 600 includes steps performed by various elements of theexemplary system, shown in FIGS. 1-3.

The method 600 starts in step 602, e.g., with the various components inthe system being initialized. Processing proceeds to store configurationinformation step 604 which includes processing sub-steps 606, 608, 610and 612.

In one embodiment, the sub-steps shown in processing step 604 areperformed by the Switched Digital Video/Video On-Demand Video Controlmodule 104 in headend 102 in association with other components of thesystem located in the hub sites e.g., hub site 1 110 of system 100. Insome embodiments, Switched Digital Video Manager module 224 and theVideo On-Demand Manager module 222 of FIG. 2 perform the processing step604 in association with the Switched Digital Video-Resource Managermodule 270 and/or Video On-Demand—Resource Manager 273. In someembodiments, the Switched Digital Video-Resource Manager module and/orthe Video On-Demand Resource Manager 273 are located in the headend 102inside of the hub site 1 110.

In processing sub-step 606 a portion of the total bandwidth available toprovide services to the service group is configured to be dedicatedbandwidth for switched digital video services. In processing sub-step608 a portion of the total bandwidth available to provide services tothe service group is configured to be dedicated bandwidth for providingvideo on-demand services. In sub-step 610 a portion of the totalbandwidth available to provide services to the service group isconfigured to be shared bandwidth for providing switched digital videoand video on-demand services. This apportionment of total bandwidth canbe understood from exemplary bandwidth allocation FIG. 4. Diagram 400 ofFIG. 4 depicts bandwidth shown along a horizontal frequency spectrum. Inthe example shown, the total bandwidth 410 is partitioned into 37frequency bands that are associated with modulators for use intransmitting video on-demand and switched digital video services to CPEdevices in a service group. The bandwidth is apportioned into dedicatedswitched digital video bandwidth 418, dedicated video on-demandbandwidth 434 and shared switched digital video and video on-demandbandwidth 424. The switched digital video dedicated bandwidth 418includes 7 frequency bands, e.g., frequency band 420, for use inproviding switched digital video services to the CPE devices of theservice group. The video on-demand dedicated bandwidth 434 includes 8frequency bands, e.g., frequency band 430, for use in providing videoon-demand services to the CPE devices of the service group. And, sharedswitched digital video/video on-demand bandwidth 424 includes 22frequency bands, e.g., frequency bands 422, 426, and 428, for use inproviding video on-demand or switched digital video services.

In processing sub-step 612, the QAM modulators, e.g., 3rd party QAMmodulators 278 and QAM modulators 276, are assigned to a portion of thefrequency of the total bandwidth corresponding to the switched digitalvideo dedicated bandwidth (e.g., bandwidth 418 of FIG. 4 or 518 of FIG.5), video on-demand dedicated bandwidth (e.g., bandwidth 434 of FIG. 4or 534 of FIG. 5), or shared switched digital video/video on-demandbandwidth (e.g., bandwidth 424 of FIG. 4 or 524 of FIG. 5). Theseassignments may be, and in some embodiments of the present inventionare, made based at least in part on whether the modulators beingassigned are capable of sharing bandwidth or have been statistically orlogically partitioned not to share bandwidth. Those modulators which arenot capable or have been partitioned not to share bandwidth are assignedto frequency bands dedicated for switched digital video or dedicatedvideo on-demand bandwidth use. For example, if one of the QAM modulatorsfrom QAM modulators 276 is unable to share bandwidth it may be, and insome embodiments is, assigned to use the frequency band 420 which ispart of the switched digital video dedicated bandwidth 418 of FIG. 4.Another QAM modulator which is unable to share bandwidth from the QAMmodulators 276 may be, and in some embodiments of the present inventionis, assigned to use the frequency band 430 which is part of dedicatedvideo on-demand bandwidth 434 of FIG. 4. An additional QAM modulatorfrom the QAM modulators 276 which is able to share bandwidth may be, andin some embodiments is, assigned to use the frequency band 426 which ispart of the shared SD/VOD bandwidth 424.

The Switched Digital Video Manager module 224 and Video On-DemandManager module 222 assign the CPE devices to the switched digital videoand video on-demand service groups respectively. The Switched DigitalVideo Manager module 224 and Video On-Demand Manager module 222 alignthe service groups and service group IDs so that the same CPE devicesare in the same service groups and are supported by a single resourcemanager, e.g., the Switched Digital Video-Resource Manager 270. The QAMmodulators are then matched to the service group they will besupporting.

The system configuration information of the present invention is storedin memory e.g., memory storage 140. The system configuration informationthat is stored includes a mapping of the following information: thebandwidth frequency bands apportioned to be dedicated for switcheddigital video services; the bandwidth frequency bands apportioned to bededicated for video on-demand services; the bandwidth frequency bandsapportioned to be shared bandwidth for use by switched digital video orvideo on-demand services; information identifying which CPE devices areassigned to each service group; the resource manager assigned to eachservice group, the QAM modulators frequency band assignments;information associating the QAM modulators, frequency bands, and servicegroups; and information regarding the CPE device identification and typeinformation (e.g., one way or two way device, single or multiple tuner).In some embodiments, some but not all of the above information is storedin memory.

In some embodiments the system configuration information is stored inmemory associated with or contained in the SDV Manager 224, the VODManager module 222, the Session Resource Manager module 220 and/or theBandwidth Sharing Mechanism module 226 for later use by one or morecomponents of the system for instance to re-configure the system afterstartup or to determine information to be used in generating and/orenforcing bandwidth sharing rules, policies and/or priorities.

Upon completion of initialization of various system components and thestorage of system configuration information in the sub-steps ofprocessing step 604, processing proceeds to processing steps 614 and616. At processing step 614, the Switched Digital Video Manager module224 transmits the CPE device to service group mapping information toeach of the CPE devices in each of the service groups and the address ofthe switched digital video server (e.g., SDV server 268) supporting theservice group. For example, the address of the SDV server 268 and theSDV service group ID 1 may be, and in some embodiments is, sent to CPEdevices 116, 118 thru 120 which are coupled to hub site 1 110 and formservice group ID 1. The VOD server address is also transmitted from theVOD Manager module 222 to each of the CPE devices, e.g., set top boxes,in the service group, e.g., CPE devices 116, 118 thru 120 for servicegroup ID 1. At processing step 616 monitoring for service requests atthe SDV server 268 in the hub site (e.g., hub site 1 110) commences.Service requests may be initiated from CPE devices, e.g., set top boxes,operators, or the service itself. An exemplary CPE device servicerequest is a change channel request, which is transmitted from a CPEdevice over the HFC network to the switched digital video server 268 athub site 1 110. When a CPE device service request is detected inmonitoring step 616 operation then proceeds to step 618 where theservice request is received. In the exemplary embodiment, the SDV serverreceives the CPE device service request, e.g., channel change requestcorresponding to a request for a program. The switched digital videoserver determines based on the switched digital video service group therequesting CPE device is assigned to whether or not the requestedprogram service is already being delivered to the switched digital videoservice group to which the CPE device is assigned. If the program isalready being provided to the service group, the switched digital videoserver 168 sends the tuning information for the program to the CPEdevice either by sending a message to the CPE device and/or via amini-carousel. In those instances in which the switched digital videoserver 268 determines that the requested service, e.g., program, is notcurrently being provided to the requesting CPE device's service groupthen processing operations proceed to processing step 620. In someembodiments, it is desirable at certain times to have a specific QAMchannel (bandwidth frequency) be vacated of a currently streamingprogram requiring that the active viewing of the stream cease. It isalso desirable to have this occur in a manner that does not requireforce-tuning of the CPE device. This functionality may, and in someembodiments, is achieved by having the switched digital video server 168direct the CPE devices tuned to the specific QAM channel to be vacatedto an a different QAM channel on which the identical service stream isset up for this purpose. This allows for a more graceful, lessdisruptive vacating of the first QAM channel to occur. Thisfunctionality is sometimes referred to as program select requestpriority tuning. When program select request priority tuning isperformed, the mini-carousel tuning information is not used. Thisfunctionality is useful for planning the “packing” of QAM channels forefficient carriage of HD service streams. That is to obtain as large aquantity of contiguous bandwidth as possible to support HDTV formatservice streams which require more contiguous bandwidth than SDTV formatservice streams.

At processing step 620 the system determines the priority of therequested service in sub-steps 622 and 624 and the priority of theon-going switched digital video and video on-demand services inprocessing steps 626 and 628 respectively. On-going services are thoseservices being delivered on the narrowcast bandwidth. On-going servicesare also referred to as services that are in operation. It will beappreciated that a service that is in operation that is an on-goingswitched digital video or video on-demand service will be utilizingnarrowcast bandwidth. In some embodiments, processing step 620 isbypassed such as when the system has sufficient unused bandwidth tosupport the newly requested service. In some embodiments, the type ofservice request is determined prior to the determination of servicepriorities. In some embodiments, when the newly received request is avideo on-demand request processing sub-step 626 is bypassed when thereis sufficient dedicated video on-demand bandwidth available with a lowerpriority than newly received request for video on-demand service. Insome embodiments, when the newly received request is a request forswitched digital video service processing of sub-step 628 is bypassedwhen there is sufficient dedicated switched digital video bandwidthavailable with a lower priority than the newly received request forswitched digital video service. In some embodiments, the processingsub-steps 626 and 628 are not performed but instead previouslydetermined priorities for on-going switched digital video and videoon-demand services are utilized. In some embodiments, the servicepriorities 622, 626, and/or 628 are determined as a function of thepriority values assigned to a subset of each service's and/or request'sattributes or features. In some embodiments, the priority valuesassigned to a service attribute or feature is determined by a policyserver. In some embodiments, the Bandwidth Sharing Mechanism module 226is a policy server that creates the service priority values associatedwith the service attributes and features and communicates those valuesto modules responsible for managing bandwidth usage.

In the exemplary embodiment of the present invention, the SwitchedDigital Video-Resource Manager module 270 in hub site 1 110 determinesthe service priorities of the requested service, the on-going switcheddigital video services and the on-going video on-demand services.Service priorities may be, and in some embodiments is stored in tablessuch as for example tables 1000, 1100, 1200, 1300, 1400, and 1500 ofFIGS. 10, 11, 12, 13, 14, and 15. In some embodiments of the presentinvention, the Session Resource Manager module 220 in the head end 102determines the priorities of the requested service, the on-goingswitched digital video services and the on-going video on-demandservices. In some embodiments, the service priority for one or more ofthe on-going switched digital video services, the on-going videoon-demand services, and/or the request for service are determined by theSwitched Digital Video Resource Manager module 270 while the remainingservices priorities are determined by the Session Resource Managermodule 220. In step 624, the cumulative service priorities for the newservice request as well as the on-going services is calculated bysumming the individual service attribute priority values correspondingto the received request and for each of on-going services separately.

Operation proceeds from step 620, via connection node A 630, to step632. At step 632, the service priorities determined in step 620 arestored for future use in memory in the headend, hub site or both. Insome embodiments, the Switched Digital Video Manager module 270 and/orthe Session Resource Manager module 220 contain memory or have memoryassociated therewith that they can access. In such embodiments, thedetermined service priorities can be stored in memory of the SwitchedDigital Video Manager module 270 and/or Session Resource Manager module220 or memory associated with these modules. Operation then proceedsfrom step 632 to decision step 634.

At decision step 634, the system determines if the received servicerequest type is a request for video on-demand or a request for switcheddigital video. If the received service request is a request for videoon-demand service then processing proceeds to decision step 638. If thereceived request is a request for switched digital video service thenprocessing proceeds to step 655 via connection node B 636. The SwitchedDigital Video-Resource Manager 270 in the hub site 1 110 performsdecision step 634. In some embodiments, the Session Resource Managermodule 220 in the head end performs decision step 634. In someembodiments the Switched Digital Video-Resource Manager module 270 islocated in the headend 102 as opposed to the hub site 1 110.

At step 638, the system determines if there is sufficient unuseddedicated video on-demand bandwidth available to support the videoon-demand service request received in step 618. If there is sufficientdedicated video on-demand bandwidth available then processing proceedsto step 640. If there is insufficient dedicated video on-demandbandwidth available then processing proceeds to step 648. In theexemplary embodiment of the invention, the operation of step 638 isperformed in the hub site 1 110 by the Switched Digital Video-ResourceManager module 270. In some embodiments, step 638 is performed in thehead end by Session Resource Manager module 220. As previouslydiscussed, in some embodiments the Switched Digital Video-ResourceManager module 270 is located in the headend 102 as opposed to the hubsite 1 110.

At step 640, the system allocates a portion of available dedicated videoon-demand bandwidth to support the service request. In the exemplaryembodiment of the invention, the Switched Digital Video-Resource Managermodule 270 performs the allocation step 640. Step 640 may be, and insome embodiments of the present invention is, performed by the SessionResource Manager module 220. After bandwidth has been allocated in step640, the system grants the service request in step 642 and then uses theallocated bandwidth to provide the requested video on-demand service instep 644, for example by providing the video on-demand content requestedon the allocated bandwidth to the CPE device which made the request. Insome embodiments, the Session Resource Manager module 220 performs thebandwidth allocation and communicates the allocation commands to theSwitched Digital Video-Resource Manager 270 in the hub site. TheSwitched Digital Video-Resource Manager 270 then assigns various QAMmodulator hardware and/or software to allocate the narrowcast bandwidthnecessary to support the requested service from the QAM modulators,e.g., 3rd Party QAM modulators 278, and binds the bandwidth to a sessionto support the requested video on-demand service. In another embodiment,the Session Resource Manager module 220, communicates directly with theQAM modulators, e.g., 3rd Party QAM modulators 278, and performs theassignments, bandwidth allocation and session setup itself. In otherembodiments, the Switched Digital Video-Resource Manager 270 performsthe bandwidth allocation process without input from the Session ResourceManager module 220. After bandwidth has been allocated and the servicerequest granted in steps 640 and 642, the Switched Digital Video Servertransmits to the requesting CPE device either directly and/or through amini-carousel the bandwidth frequency the requested service will beprovided on and utilizes the allocated bandwidth to provide the videoon-demand content requested by the CPE device. Processing then proceedsto end step 646 where this portion of the processing associated with therequest for service concludes but overall system operation continues.For example, throughout the aforementioned steps the system has been andcontinues monitoring for service requests in step 616 and processing anyservice requests detected.

As discussed above, when it is determined in decision step 638 thatthere is insufficient unused dedicated video on-demand bandwidthavailable to support the requested video on-demand service requestprocessing proceeds to step 648. At step 648, the system compares thepriority of the requested video on-demand service to the priorities ofthe on-going switched digital video services using shared bandwidth andthe priorities of on-going video on-demand services. In someembodiments, the Session Resource Manager module 220 performs thisoperation using the service priorities determined in step 620 and whichare stored in memory in step 632. In step 650, the system makes adecision as to whether the priority of the requested service exceeds thepriority of one or more services to which it was compared in step 648.If the requested service's priority does exceed the priority of one ormore of the services to which it is compared then processing proceeds todecision step 690 via connection node C 652. If the requested service'spriority does not exceed the priority of one or more services to whichit was compared in step 648 then processing proceeds to step 698 viaconnecting node D 654.

In decision step 690, the system determines if the on-going serviceswith a lower priority than the requested video on-demand service occupysufficient bandwidth to support the requested video on-demand service.If the lower priority on-going services do not occupy sufficientbandwidth to support the requested service processing proceeds to step698 via connection node D 654. If the lower priority on-going servicesdo occupy sufficient bandwidth to support the requested service thenprocessing proceeds to step 692. In an exemplary embodiment of thepresent invention, processing operation step 692 is performed in theSwitched Digital Video-Resource Manager module 270. In some embodimentsof the present invention, decision step 690 is performed in the SessionResource Manager module 220.

In processing step 692, the system performs a bandwidth session release,for example it terminates one or more on-going services, to releasesufficient resources that is narrowcast bandwidth to support therequested service. In an exemplary embodiment this operation isperformed by the Switched Digital Video-Resource Manager 270. In someembodiments, this operation is performed by the Session Resource Managermodule 220. The determination of which lower priority service orservices to terminate may be, and in some embodiments is, made byidentifying and terminating those services with the lowest priorityuntil sufficient bandwidth is available to support the requestedservice.

From step 692 processing proceeds to step 694. At step 694, the systemallocates a portion of available dedicated video on-demand and/or sharedbandwidth to support the service request. In some embodiments, a portionof the available bandwidth may be, and in some instances is, all of theavailable bandwidth. The allocation process of step 694 may be, and insome embodiments is, performed by the Session Resource Manager module220 and/or the Switched Digital Video-Resource Manager module 270.

After bandwidth has been allocated in step 694, the system grants theservice request in step 695 and then uses the allocated bandwidth toprovide the requested video on-demand service in step 696, for exampleby providing the video on-demand content requested on the allocatedbandwidth to the CPE device which made the request. In the exemplaryembodiment, the Switched Digital Video-Resource Manager module 270performs the bandwidth allocation process. In some embodiments, theSession Resource Manager module 220 performs the bandwidth allocationand communicates the allocation commands to the Switched DigitalVideo-Resource Manager module 270 which may be located in either the hubsite or headend. The Switched Digital Video-Resource Manager module 270then assigns various QAM modulator hardware and/or software to theallocated narrowcast bandwidth necessary to support the requestedservice from the QAM modulators, e.g., 3rd Party QAM modulators 278, andbinds the bandwidth to a session to support the requested videoon-demand service. In another embodiment, the Session Resource Managermodule 220, communicates directly with the QAM modulators, e.g., 3rdParty QAM modulators 278, and performs the assignments, bandwidthallocation and session setup itself. After bandwidth has been allocatedand the service request granted in steps 694 and 695, the SwitchedDigital Video Server transmits to the requesting CPE device eitherdirectly and/or through a mini-carousel the bandwidth frequency therequested service will be provided on. The allocated bandwidth is thenutilized to provide the video on-demand content requested by the CPEdevice. The video on-demand content is provided in the exemplaryembodiment from the video on-demand server 272 located in the hub site 1110. In some embodiments, the video on-demand server 272 is located inheadend 102. In some embodiments, the video on-demand server is coupledto the system but not located within the system. Processing thenproceeds to end step 697 where this portion of the processing associatedwith the request for service concludes but overall system operationcontinues. For example, throughout the aforementioned steps the systemhas been and continues monitoring for service requests in step 616 andprocessing any service requests detected.

As discussed above, if the request received in step 616 is determined tobe a switched digital video service request in decision step 634 thenprocessing proceeds at step 655. In step 655, the system compares thepriority of the requested switched digital video service to thepriorities of the on-going switched digital video services and the videoon-demand services using shared bandwidth. In an exemplary embodiment,the comparison step 655 is performed by Switched Digital—ResourceManager module 270 in the hub site. In some embodiments, this step maybe, and is performed by the Session Resource Manager module 220 in theheadend 102 or by the combination of the Session Resource Manager module220 and the Switched Digital Video-Resource Manager module 270.Processing then proceeds to decision step 656. At processing step 656,the system determines if the priority of the requested service exceedsthe priority of one or more services to which it was compared in step655. If the service request has a lower priority than the services towhich it was compared then processing proceeds to step 698 viaconnection node D 654.

In decision step 658, the system determines if the on-going serviceswith a lower priority than the requested switched digital video serviceoccupy sufficient bandwidth to support the requested switched digitalvideo service. If the lower priority on-going services do not occupysufficient bandwidth to support the requested service processingproceeds to step 698 via connection node D 654. If the lower priorityon-going services do occupy sufficient bandwidth to support therequested service then processing proceeds to step 660. Processingoperation steps 656 and 658 are performed in an exemplary embodiment bythe Switched Digital Video-Resource Manager module 270. In someembodiments of the present invention, decision steps 656 and 658 areperformed by Session Resource Manager module 220.

In processing step 660, the system performs a bandwidth session release,for example it terminates one or more on-going services, to releasesufficient resources that is narrowcast bandwidth to support therequested service. This operation is performed by the Switched DigitalVideo-Resource Manager module 270 in an exemplary embodiment. In someembodiments, the Session Resource Manager module 220 or the SessionsResource Manager module 220 and the Switched Digital Video-ResourceManager module 270 perform this operation. The determination of whichlower priority service or services to terminate in at least someembodiments is made by identifying and terminating those services withthe lowest priority until sufficient bandwidth is available to supportthe requested service.

From step 660 processing proceeds to step 662. At step 662, the systemallocates a portion of available dedicated switched digital video and/orshared bandwidth to support the service request. In some embodiments, aportion of the available bandwidth may be, and in some instances is, allof the available bandwidth. In some embodiments, the allocation processof step 662 is performed by the Session Resource Manager module 220and/or the Switched Digital Video-Resource Manager 270.

After bandwidth has been allocated in step 662, the system grants theservice request in step 664 and then uses the allocated bandwidth toprovide the requested switched digital video service in step 666, forexample by providing the switched digital video content requested on theallocated bandwidth to the CPE device which made the request. In anexemplary embodiment, the Switched Digital Video-Resource Manager module270 performs the bandwidth allocation process. In some embodiments, theSession Resource Manager module 220 performs the bandwidth allocationand communicates the allocation commands to the Switched DigitalVideo-Resource Manager 270 in the hub site. The Switched DigitalVideo-Resource Manager then assigns various QAM modulator hardwareand/or software to the allocated narrowcast bandwidth necessary tosupport the requested service from the QAM modulators, e.g., 3rd PartyQAM modulators 278 and/or QAM modulators 276, and binds the bandwidth toa session to support the requested switched digital video service. Inanother embodiment, the Session Resource Manager module 220,communicates directly with the QAM modulators, e.g., 3rd Party QAMmodulators 278 or QAM Modulators 276, and performs the assignments,bandwidth allocation and session setup itself. After bandwidth has beenallocated and the service request granted in steps 662 and 664, theSwitched Digital Video Server transmits to the requesting CPE deviceeither directly and/or through a mini-carousel the bandwidth frequencythe requested service will be provided on. The SDV server 268 thenutilizes the allocated bandwidth to provide the switched digital videocontent requested by the CPE device. The switched digital video contentmay be, and in some embodiments is, received by the headend 102 preparedfor transmission in staging processor 250 of the SDV Media Path module106, encrypted by bulk encryptor 254 and then selected for transmissionand routed to the hub site 1 110 by switch/router 256 via link 264 toedge switch/router 274 where the content is switched to the modulator,e.g., one of the 3rd Party QAM modulators 278, assigned to transmit theswitched digital video content on the allocated bandwidth. The QAMmodulator then sends the switched digital video content over link 294 tothe combiner 282 which sends the content over the HFC network 212 to theCPE devices in the service group which included the CPE device thatrequested the service. Processing then proceeds to end step 668 wherethis portion of the processing associated with the request for serviceconcludes but overall system operation continues. For example,throughout the aforementioned steps the system has been and continuesmonitoring for service requests in step 616 and processing any servicerequests detected.

At step 698, the system denies the request for service. Step 698 in anexemplary embodiment is performed by the Switched Digital Video-ResourceManager 270. In some embodiments the Session Resource Manager module 220or the Session Resource Manager module 220 and the Switched DigitalVideo-Resource Manager module 270. Processing then proceeds to end step699 where this portion of the processing associated with the request forservice concludes but overall system operation continues. For example,throughout the aforementioned steps the system has been and continuesmonitoring for service requests in step 616 and processing any servicerequests detected.

While a logical sequencing of the processing steps of the exemplaryembodiments of the methods, routines and subroutines of the presentinvention have been shown, the sequencing is only exemplary and theordering of the steps may be varied.

An exemplary method in accordance with the present invention is a methodof providing video on-demand and switched digital video using bandwidthto a first set of customer premise equipment devices, the methodcomprising: using a first dedicated portion of said bandwidth to providevideo on-demand services; using a second dedicated portion of saidbandwidth to provide switched digital video services; and using a thirdportion of said bandwidth to provide both video on-demand and switcheddigital video services, said third portion of said bandwidth beingavailable for communicating either video on-demand or switched digitalvideo, the size of a video on-demand portion of third portion ofbandwidth varying as a function of requests for video on-demand contentreceived from one or more customer premise equipment devices and a videoon-demand service priority relative to a switched digital video servicepriority. The method may be, and in some embodiments is, implemented,wherein said video on-demand service priority is a priority for a videoon-demand service; and said switched digital video service priority is apriority for a switched digital video service. In some embodiments, thedescribed method further comprises: responding to a request for servicebased on the type of service requested; wherein responding to therequest for service includes allocating bandwidth in the first dedicatedportion of said bandwidth if the requested service is a video on-demandservice and the first dedicated portion of said bandwidth has sufficientunused bandwidth available to support the requested video on-demandservice. In some embodiments, the method includes the prioritization ofservices and requests for determining the allocation of bandwidth. Insuch an embodiment, when said request for service is a request for videoon-demand service and said first dedicated portion of said bandwidthdoes not have sufficient unused bandwidth available to support therequested video on-demand service, the method includes determining ifthe requested video on-demand service has a higher priority than anotherservice currently utilizing either some of said third (shared) portionof bandwidth or some of said first (VOD) portion of bandwidth.

Another exemplary method of providing video on-demand and switcheddigital video using bandwidth to a first set of customer premiseequipment devices in accordance with the present invention, is a methodcomprising: using a first dedicated portion of said bandwidth to providevideo on-demand services; using a second dedicated portion of saidbandwidth to provide switched digital video services; and using a thirdportion of said bandwidth to provide both video on-demand and switcheddigital video services, said third portion of said bandwidth beingavailable for communicating either video on-demand or switched digitalvideo, the size of a video on-demand portion of third portion ofbandwidth varying as a function of requests for video on-demand contentreceived from one or more customer premise equipment devices and a videoon-demand service priority relative to a switched digital video servicepriority; and wherein the system implementing the method responds to arequest for service based on the type of service requested. In thoseinstances in which the request for service is a request for a switcheddigital video service, the system, e.g., switched digital video-resourcemanager module 270 of the system illustrated in FIG. 2, determines ifthe requested switched digital video service has a higher priority thananother switched digital video service currently utilizing either someof said third (shared) portion of bandwidth or some of said second (SDV)portion of bandwidth. In some embodiments of this exemplary method, thestep of determining if the requested switched digital video service hasa higher priority is performed without first checking if there is unusedbandwidth in either said second or third portions of bandwidth. In someembodiments of the exemplary method, the requested switched digitalvideo service has a priority which is higher than any inactive switcheddigital video service utilizing a portion of said second or thirdbandwidth.

In some variants of the exemplary method described above, the methodutilizes portions of said second and third portions of bandwidth whichare not being utilized by an active switched digital video service or avideo on-demand service to communicate data corresponding to one or moreinactive switched digital video services. In some embodiments of thisexemplary method of providing video on-demand and switched digital videomore than 90% of the second and third portions of bandwidth are utilizedon a continuous basis. In some instances of the exemplary method, saidsecond and third portions of bandwidth are kept fully occupied. In someembodiments of this exemplary method, this is achieved by having apolicy server, e.g., bandwidth sharing mechanism module 226 of headend102 generate and distribute to resource managers, e.g., switched digitalvideo-resource manager module 270, policies, priorities and/or rules tomanage the available bandwidth the implementation of which will achievethe aforementioned bandwidth usage.

In some embodiments in accordance with the present invention, aninactive switched digital video service which utilizes some of saidsecond and third portions of bandwidth is a service without currentlyactive viewers. In some embodiments, it is a service without currentlyregistered users.

Another exemplary method of providing video on-demand and switcheddigital video using bandwidth to a first set of customer premiseequipment devices in accordance with the present invention, is a methodcomprising: using a first dedicated portion of said bandwidth to providevideo on-demand services; using a second dedicated portion of saidbandwidth to provide switched digital video services; and using a thirdportion of said bandwidth to provide both video on-demand and switcheddigital video services, said third portion of said bandwidth beingavailable for communicating either video on-demand or switched digitalvideo, the size of a video on-demand portion of third portion ofbandwidth varying as a function of requests for video on-demand contentreceived from one or more customer premise equipment devices and a videoon-demand service priority relative to a switched digital video servicepriority; and wherein the system implementing the method responds to arequest for service based on the type of service requested. In thoseinstances in which the request for service is a request for a switcheddigital video service, the system, e.g., switched digital video-resourcemanager module 270 of the system illustrated in FIG. 2, determines ifthe requested switched digital video service has a higher priority thananother switched digital video service currently utilizing either someof said third (shared) portion of bandwidth or some of said second (SDV)portion of bandwidth and in those instances when said request forservice is a request for video on-demand-service and said firstdedicated portion of said bandwidth does not have sufficient unusedbandwidth available to support the requested video on-demand service,the system, e.g., a switched digital video-resource manager module ofthe system illustrated in FIG. 2, determines if the requested videoon-demand service has a higher priority than another service currentlyutilizing either some of said third (shared) portion of bandwidth orsome of said first (VOD) portion of bandwidth. In some embodiments,prior to determining if the requested video on-demand service has ahigher priority than another service, the priority of the requestedvideo on-demand service as a function of at least two of: a videoon-demand service type, time of day, stream type, programming packagetype, stream format type, tuner priorities, and viewership priority isdetermined. In some embodiments of this exemplary method, the step ofdetermining if the requested switched digital video service has a higherpriority is performed without first checking if there is unusedbandwidth in either said second or third portions of bandwidth. In someembodiments of this method, the numerical priority values associatedwith different service features are provided by a policy server whichsupplies priority information to a plurality of hub sites. In suchinstances, the step of determining the priority of the requested videoon-demand service may be, and in some embodiments is, performed at a hubsite based on service features corresponding to the requested videoon-demand session and the priority values specified by said policyserver, said policy server being located remotely from said hub site.

In some embodiments of this exemplary method, the step of determiningthe priority of the requested video on-demand service includes—summingnumerical priority values associated with different service featurescorresponding to the requested video on-demand service to generate saidpriority of the requested video on-demand service.

In another aspect of the exemplary method, in accordance with thepresent invention, the hub site serving a VOD service group andcorresponding SDV service group operates as a policy enforcement pointto implement priority policies set by said policy server based oninformation locally available at or logically associated with said hubsite (and which in some cases is not available at the policy server atthe time the priority determination is made at the hub site).

In some variants of the exemplary method, prior to performing the stepof determining if the requested video on-demand service has a higherpriority than another service, determining the priority of the anotherservice as a function of at least two of: the service type of theanother service, time of day, time of day, stream type, programmingpackage type, stream format type, tuner priorities, and viewershippriority.

In some embodiments of the exemplary method the step of determining thepriority of the requested video on-demand service includes—summingnumerical priority values associated with different service features togenerate said priority of the requested video on-demand service.

In some embodiments of the exemplary method, the step of determining ifthe requested video on-demand service has a higher priority than anotherservice currently utilizing either some of said third (shared) portionof bandwidth or some of said first (VOD) portion of bandwidth furtherincludes: analyzing data pertaining to the historical behavior of usersof the first set of customer premise equipment devices including theusers' viewing habits for the current time and day of the week; andbased upon that analysis giving a higher priority to services that arefrequently requested by multiple users within the first set of customerpremise equipment devices at that time on that day of the week than toother service requests.

In another exemplary method of providing video on-demand and switcheddigital video using bandwidth to a first set of customer premiseequipment devices in accordance with the present invention, the methodcomprises: using a first dedicated portion of said bandwidth to providevideo on-demand services; using a second dedicated portion of saidbandwidth to provide switched digital video services; and using a thirdportion of said bandwidth to provide both video on-demand and switcheddigital video services, said third portion of said bandwidth beingavailable for communicating either video on-demand or switched digitalvideo, the size of a video on-demand portion of third portion ofbandwidth varying as a function of requests for video on-demand contentreceived from one or more customer premise equipment devices and a videoon-demand service priority relative to a switched digital video servicepriority; and said first, second and third portions of bandwidthcorrespond a single group of quadrature amplitude modulatorscorresponding to both a Video on-Demand Service Group and a SwitchedDigital Service Group used to provide narrowcast digital services to asingle group of customer premise equipment devices. In some embodiments,the method further comprises: transmitting a VOD Service Group ID and aSDV Service Group ID using in-band signaling to said single group ofcustomer premise equipment devices, said in-band signaling using acommunications band which is also used to provide at least one of videoon-demand program content and switched digital video broadcast programcontent. In some instances of this exemplary method said VOD serviceGroup ID and said SDV service Group ID map to the same group of customerpremise equipment devices. Additionally, in some embodiments, the methodincludes transmitting a VOD IP port identifier and a VOD sessionresource manager IP address to the customer premise equipment devices.In some embodiments, the video on-demand server 272 transmits thisinformation. In some variants of this method different VOD sessionresource manager IP addresses are used for different geographic regionsand correspond to different session resource managers.

An exemplary system, in accordance with the present invention, includesa content distribution system for providing video on-demand and switcheddigital video to a first set of customer premise equipment devices,e.g., service group of CPE devices, using bandwidth, the systemcomprising: a resource manager module configured to allocate a firstdedicated portion of said bandwidth for use in providing video on-demandservices, a second dedicated portion of said bandwidth for use inproviding switched digital video services; and a third portion of saidbandwidth to provide both video on-demand and switched digital videoservices, said third portion of said bandwidth being available forcommunicating either video on-demand or switched digital video, the sizeof a video on-demand portion of third portion of bandwidth varying as afunction of requests for video on-demand content received from one ormore customer premise equipment devices and a video on-demand servicepriority relative to a switched digital video service priority; and aset of quadrature amplitude modulators coupled to the resource managermodule for modulating data on the allocated portions of bandwidth inaccordance with said bandwidth allocation by said resource manager. Insome embodiments, the resource manager module may be, and is, a servercontaining software instructions. In some embodiments the resourcemanager is also configured to respond to a request for service based onthe type of service requested and if the request is for switched digitalvideo service the response includes determining if the requestedswitched digital video service has a higher priority than anotherswitched digital video service currently utilizing either some of saidthird (shared) portion of bandwidth or some of said second (SDV) portionof bandwidth; and if the request is for video on-demand-service theresponse includes determining if said first dedicated portion of saidbandwidth does not have sufficient unused bandwidth available to supportthe requested video on-demand service and if the requested videoon-demand service has a higher priority than another service currentlyutilizing either some of said third (shared) portion of bandwidth orsome of said first (VOD) portion of bandwidth.

In another embodiment, in accordance with the present invention, theresource manager module of the aforementioned exemplary system isfurther configured to respond to a request for service based on the typeof service requested; and if the request is for switched digital videoservice the response includes determining if the requested switcheddigital video service has a higher priority than another switcheddigital video service currently utilizing either some of said third(shared) portion of bandwidth or some of said second (SDV) portion ofbandwidth; and if the request is for video on-demand-service theresponse includes determining if said first dedicated portion of saidbandwidth does not have sufficient unused bandwidth available to supportthe requested video on-demand service and if the requested videoon-demand service has a higher priority than another service currentlyutilizing either some of said third (shared) portion of bandwidth orsome of said first (VOD) portion of bandwidth. In this embodiment, saidresource manager module, may be and in some instances is, configured: todetermine, prior to determining if the requested video on-demand servicehas a higher priority than another service, the priority of therequested video on-demand service as a function of at least two of: avideo on-demand service type, time of day, stream type, programmingpackage type, stream format type, tuner priorities, and viewershippriority; and wherein determining the priority of the requested videoon-demand service includes summing numerical priority values associatedwith different service features corresponding to the requested videoon-demand service to generate said priority of the requested videoon-demand service. In some embodiments, this exemplary system furthercomprises a policy server which is configured to supply priorityinformation including numerical priority values associated withdifferent service features to said manager module. In some embodiments,the bandwidth sharing mechanism module includes the policy server. Insome embodiments, a resource manager such as the Session ResourceManager module 220 or the Switched Digital Video Server—Resource Managermodule 270 of FIG. 2 performs the function of the policy server.

In some embodiments of the exemplary systems described above inaccordance with the present invention, the set of quadrature amplitudemodulators correspond to both a Video on-Demand Service Group and aSwitched Digital Service Group used to provide narrowcast digitalservices to a single group of customer premise equipment devices. Insuch systems, the resource manager module may be, and in some instancesis, configured to transmit a VOD Service Group ID and a SDV ServiceGroup ID using in-band signaling to said single group of customerpremise equipment devices, said in-band signaling using a communicationsband which is also used to provide at least one of video on-demandprogram content and switched digital video broadcast program content;and wherein said VOD service Group ID and said SDV service Group ID mapto the same group of customer premise equipment devices.

Another exemplary embodiment of the present invention includes the useof a non-transitory computer readable medium having machine executableinstructions stored thereon for controlling the distribution of videoon-demand and switched digital video using bandwidth to a first set ofcustomer premise equipment devices, the non-transitory computer readablemedium including: code for controlling a processor's, e.g., switcheddigital video resource manager module's processor's, use of a firstdedicated portion of said bandwidth to provide video on-demand services;code for controlling the processor's use of a second dedicated portionof said bandwidth to provide switched digital video services; and codefor controlling the processor use of a third portion of said bandwidthto provide both video on-demand and switched digital video services,said third portion of said bandwidth being available for communicatingeither video on-demand or switched digital video, the size of a videoon-demand portion of third portion of bandwidth varying as a function ofrequests for video on-demand content received from one or more customerpremise equipment devices and a video on-demand service priorityrelative to a switched digital video service priority.

In various embodiments system elements described herein are implementedusing one or more modules which are used to perform the stepscorresponding to one or more methods of the present invention, forexample, a resource manager module performs the step of responding to arequest for service based on the type of service requested. Each stepmay be performed by one or more different software instructions executedby a computer processor, e.g., a central processing unit (CPU). In someembodiments the modules may be and are implemented in software. In someembodiments, the modules may be and are implemented as servers. In someembodiments the modules may be, and are implemented in hardware, e.g.,as circuits. In some embodiments the modules may be, and are,implemented in a combination of hardware and software.

At least one system implemented in accordance with the present inventionincludes a means for implementing each of the various steps which arepart of the methods of the present invention. Each means may be, e.g.,an instruction, processor, hardware circuit and/or combination ofelements used to implement a described step. Many of the above describedmethods or method steps can be implemented using machine, e.g.,computer, executable instructions, such as software, included in amachine, e.g., computer, readable medium used to control a machine,e.g., general purpose computer with or without additional hardware, toimplement all or portions of the above described methods, e.g., in oneor more nodes. The machine readable medium may be, e.g., a memorydevice, e.g., RAM, floppy disk, etc. Accordingly, among other things,the present invention is directed to a machine-readable medium includingmachine executable instructions for causing a machine, e.g., processorand associated hardware, to perform one or more of the steps of theabove-described method(s).

Numerous additional embodiments, within the scope of the presentinvention, will be apparent to those of ordinary skill in the art inview of the above description and the claims which follow. Suchvariations are to be considered within the scope of the invention.

What is claimed is:
 1. A method of providing video on-demand andswitched digital video using bandwidth to a first set of customerpremise equipment devices, the method comprising: apportioning saidbandwidth so that it includes a first portion, a second portion and athird portion, said first portion of bandwidth being dedicated forcommunicating video-on demand, said second portion of bandwidth beingdedicated for communicating switched digital video, and said thirdportion of bandwidth being available for communicating either videoon-demand or switched digital video; using said first dedicated portionof said bandwidth to provide video on-demand services; using said seconddedicated portion of said bandwidth to provide switched digital videoservices; and using said third portion of said bandwidth to provide bothvideo on-demand and switched digital video services, said third portionof said bandwidth being available for communicating either videoon-demand or switched digital video, the size of a video on-demandportion of said third portion of bandwidth varying as a function ofrequests for video on-demand content received from one or more customerpremise equipment devices and a video on-demand service priorityrelative to a switched digital video service priority.
 2. The method ofclaim 1, wherein said video on-demand service priority is a priority fora video on-demand service; wherein said switched digital video servicepriority is a priority for a switched digital video service; whereinsaid apportionment of said first, second and third portions of bandwidthdo not change from a first time to a second time; and wherein said sizeof said video-on demand portion of said third portion of bandwidthincreases from said first time to said second time.
 3. The method ofclaim 1, further comprising: responding to a request for service basedon the type of service requested; wherein responding to the request forservice includes allocating bandwidth in the first dedicated portion ofsaid bandwidth if the requested service is a video on-demand service andthe first dedicated portion of said bandwidth has sufficient unusedbandwidth available to support the requested video on-demand service;and wherein using said first dedicated portion of said bandwidth toprovide video on-demand services includes operating a communicationsdevice which does not support bandwidth sharing to use at least aportion of said first dedicated portion of said bandwidth.
 4. The methodof claim 3, further comprising: when said request for service is arequest for video on-demand service and said first dedicated portion ofsaid bandwidth does not have sufficient unused bandwidth available tosupport the requested video on-demand service, determining if therequested video on-demand service has a higher priority than anotherservice currently utilizing either some of said third portion ofbandwidth or some of said first portion of bandwidth.
 5. The method ofclaim 1, further comprising: responding to a request for service basedon the type of service requested; when said request for service is arequest for a switched digital video service determining if therequested switched digital video service has a higher priority thananother switched digital video service currently utilizing either someof said third portion of bandwidth or some of said second portion ofbandwidth.
 6. The method of claim 5 wherein the requested switcheddigital video service has a priority which is higher than any inactiveswitched digital video service utilizing a portion of said second orthird bandwidth, further comprising: utilizing portions of said secondand third portions of bandwidth which are not being utilized by anactive switched digital video service or a video on-demand service tocommunicate data corresponding to one or more inactive switched digitalvideo services.
 7. The method of claim 5, further comprising: when saidrequest for service is a request for video on-demand-service and saidfirst dedicated portion of said bandwidth does not have sufficientunused bandwidth available to support the requested video on-demandservice, determining if the requested video on-demand service has ahigher priority than another service currently utilizing either some ofsaid third portion of bandwidth or some of said first portion ofbandwidth.
 8. The method of claim 7, further comprising: prior todetermining if the requested video on-demand service has a higherpriority than another service, determining the priority of the requestedvideo on-demand service as a function of at least two of: a videoon-demand service type, time of day, stream type, programming packagetype, stream format type, tuner priorities, and viewership priority. 9.The method of claim 8, further comprising: prior to determining if therequested video on-demand service has a higher priority than anotherservice, determining the priority of the another service as a functionof at least two of: the service type of the another service, time ofday, time of day, stream type, programming package type, stream formattype, tuner priorities, viewership priority.
 10. The method of claim 8,wherein the determining if the requested video on-demand service has ahigher priority than another service currently utilizing either some ofsaid third portion of bandwidth or some of said first portion ofbandwidth further includes: analyzing data pertaining to the historicalbehavior of users of the first set of customer premise equipment devicesincluding the users' viewing habits for the current time and day of theweek; and based upon that analysis giving a higher priority to servicesthat are frequently requested by multiple users within the first set ofcustomer premise equipment devices at that time on that day of the weekthan to other service requests.
 11. The method of claim 1, wherein saidfirst, second and third portions of bandwidth correspond a single groupof quadrature amplitude modulators corresponding to both a Videoon-Demand Service Group and a Switched Digital Service Group used toprovide narrowcast digital services to a single group of customerpremise equipment devices.
 12. The method of claim 11, furthercomprising: transmitting a VOD Service Group ID and a SDV Service GroupID using in-band signaling to said single group of customer premiseequipment devices, said in-band signaling using a communications bandwhich is also used to provide at least one of video on-demand programcontent and switched digital video broadcast program content.
 13. Themethod of claim 12, wherein said VOD service Group ID and said SDVservice Group ID map to the same group of customer premise equipmentdevices.
 14. The method of claim 13, further comprising: transmitting aVOD IP port identifier and a VOD session resource manager IP address.15. The method of claim 14 wherein different VOD session resourcemanager IP addresses are used for different geographic regions andcorrespond to different session resource managers.
 16. A contentdistribution system for providing video on-demand and switched digitalvideo to a first set of customer premise equipment devices usingbandwidth, the system comprising: a resource manager configured toallocate a first dedicated portion of said bandwidth for use inproviding video on-demand services, a second dedicated portion of saidbandwidth for use in providing switched digital video services, and athird portion of said bandwidth to provide both video on-demand andswitched digital video services, said third portion of said bandwidthbeing available for communicating either video on-demand or switcheddigital video, the size of a video on-demand portion of third portion ofbandwidth varying as a function of requests for video on-demand contentreceived from one or more customer premise equipment devices and a videoon-demand service priority relative to a switched digital video servicepriority; and a set of quadrature amplitude modulators coupled to theresource manager for modulating data on the allocated portions ofbandwidth in accordance with said bandwidth allocation by said resourcemanager.
 17. The system of claim 16, wherein said resource manager isfurther configured to respond to a request for service based on the typeof service requested; wherein if the request is for switched digitalvideo service the response includes determining if the requestedswitched digital video service has a higher priority than anotherswitched digital video service currently utilizing either some of saidthird portion of bandwidth or some of said second portion of bandwidth;and if the request is for video on-demand-service the response includesdetermining if said first dedicated portion of said bandwidth does nothave sufficient unused bandwidth available to support the requestedvideo on-demand service and if the requested video on-demand service hasa higher priority than another service currently utilizing either someof said third portion of bandwidth or some of said first portion ofbandwidth.
 18. The system of claim 16, wherein said set of quadratureamplitude modulators correspond to both a Video on-Demand Service Groupand a Switched Digital Service Group used to provide narrowcast digitalservices to a single group of customer premise equipment devices. 19.The system of claim 18, wherein said resource manager is furtherconfigured to transmit a VOD Service Group ID and a SDV Service Group IDusing in-band signaling to said single group of customer premiseequipment devices, said in-band signaling using a communications bandwhich is also used to provide at least one of video on-demand programcontent and switched digital video broadcast program content; andwherein said VOD service Group ID and said SDV service Group ID map tothe same group of customer premise equipment devices.
 20. Anon-transitory computer readable medium having machine executableinstructions stored thereon for controlling the distribution of videoon-demand and switched digital video using bandwidth to a first set ofcustomer premise equipment devices, the non-transitory computer readablemedium including: code for controlling a processor to use a firstdedicated portion of said bandwidth to provide video on-demand services;code for controlling the processor to use a second dedicated portion ofsaid bandwidth to provide switched digital video services; and code forcontrolling the processor to use a third portion of said bandwidth toprovide both video on-demand and switched digital video services, saidthird portion of said bandwidth being available for communicating eithervideo on-demand or switched digital video, the size of a video on-demandportion of third portion of bandwidth varying as a function of requestsfor video on-demand content received from one or more customer premiseequipment devices and a video on-demand service priority relative to aswitched digital video service priority.